button cycled NeoPixel on Digispark ATtiny85

Not sure if I ask really good questions or really bad questions since I never received any replies. Pretty sure it's the latter.

Phase 1 = Get buttoncycler example/circuit to work and customize showTypes (complete)
Phase 2 = Have current showType stop (even in the middle of running) when button pressed and advance to next showType (case)
Phase 3a = Have current showType repeat until button pressed (complete)
Phase 3b = Have current showType repeat until uC goes to sleep from 5-min idle timer
Phase 4 = Add a sleep mode to wake on external interrupt (button on P2)
Phase 5 = Optimize to reduce uAh and mAh

Made some changes to the code that got me some progress after 2-3 days of reading/editing. Any suggestions on how to stop a "for loop" or "for loops" nested together when I press a button? I've tried while, do/while, goto, if, break, return, continue.... but nothing seems to work as intended (although I'm sure it's working as written). I attached screencaps of a function (showType) that I wanted to interrupt. The examples/references in the IDE and on the website do not normally involve "for loops." I'm hesitant to try an interrupt because I want to use the button pin as an external interrupt when Sparky is asleep. Can I have 1 pin do 2 interrupts??

/* Cycle NeoPixels with button using Digispark ATtiny85 (microUSB version)
 *  Button on P2 (PCINT0) cycles through different modes (cases). Mode stops and switches to the
 *  next mode when button is pressed.  Current mode plays until button is pressed or goes into 
 *  low power mode after 5 minutes.  uC wakes on button press on P2 (PCINT0) and continues program.
 *  User can turn off circuit with switched attached to VIN.  User needs to press the 
 *  button once to start the first animation!
 *  Momentary push button is wired to connect P2 to ground. P2 kept high by internal pullup.
 *  NeoPixel data in connected in series with a 330 ohm resistor to P0.
 *  Neopixel 5V and GND pins connected to Digispark ATtiny85 power rail 5V and GND pins, respectively. 
 *  Program will eventually include SLEEP_MODE_PWR_DOWN & wdt_disable so it only awakens with PCINT0
 *  
 *  ISSUE LOG:
 *  1. Button press does not stop showType in middle of function
 *  2. showType runs until button pressed nut NOT 5-min sleep timer
 *  3. Minimize power draw when awake
 *  4. Remove delay() in showType functions
 */
 
#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
 #include <avr/power.h>
#endif

#define BUTTON_PIN   2    // Digital IO pin connected to the button.  

#define PIXEL_PIN    0    // Digital IO pin connected to the NeoPixels.

#define PIXEL_COUNT 9


Adafruit_NeoPixel strip = Adafruit_NeoPixel(PIXEL_COUNT, PIXEL_PIN, NEO_GRB + NEO_KHZ800);

bool buttonPressed = false;
bool oldState = HIGH;
bool newState = HIGH;
int showType = 0;

unsigned long startMillis;
unsigned long currentMillis;
const int debouncePeriod = 20;  
unsigned long debounceStartMillis;

// Neopixel color test
void testPixels() 
{
  colorWipe(strip.Color(255, 0, 0), 50); // Red
  colorWipe(strip.Color(0, 0, 255), 50); // Blue  
  colorWipe(strip.Color(0, 255, 0), 50); // Green
}

// Check state of button
void checkButton()
{
    // Get current button state
  newState = digitalRead(BUTTON_PIN);
  
  // Check if state changed from high to low (button press)
  if (newState != oldState)
  {
    if (currentMillis - debounceStartMillis >= debouncePeriod)
    {
      if (digitalRead(BUTTON_PIN) == LOW)    // if button still pressed
      {
        newState = LOW;
        oldState += newState;                // Update oldState to last button state (newState)
        buttonPressed = true;                // trying to set flag that button is pressed
      }
    }
  }
  else 
  {
    newState = HIGH;
    oldState += newState;
    buttonPressed = false;
  }                                              
}

void setup() 
{
/*  // This is for Trinket 5V 16MHz, you can remove these three lines if you are not using a Trinket
  #if defined (__AVR_ATtiny85__)
    if (F_CPU == 16000000) clock_prescale_set(clock_div_1);
  #endif
  // End of trinket special code
*/  
  pinMode(PIXEL_PIN, OUTPUT);
  digitalWrite(BUTTON_PIN, HIGH);  // activate pull-up resistor to set pin HIGH
  
  strip.begin();
  strip.setBrightness(50);  // dim output to conserve battery
  strip.show(); // Initialize all pixels to 'off'

  testPixels();
 
  startMillis = millis();  //initial start time

}

void loop() 
{
  //get the current "time" 
  currentMillis = millis();  

  // Call to checkButton function
  checkButton();                               
      
  if (buttonPressed == true)
  {
    showType++;
    if (showType > 8)
    {
    showType = 0;
    }
  }
  startShow(showType);

//  oldState = newState;
}

void startShow(int i) {
  switch(i) {
    case 0: checkButton();
            colorWipe(strip.Color(0, 0, 0), 50);         // Black/off 
            break;
    case 1: checkButton();
            colorWipe(strip.Color(153, 0, 255), 200);    // Purple: Signifies pain, suffering, grief, and mourning
            colorWipe(strip.Color(255, 0, 153), 200);    // Pink: Celebration 
            colorWipe(strip.Color(127, 127, 127), 200);  // White: Purity and hope
            colorWipe(strip.Color(200, 51, 0), 200);     // Orange: Sun 
            colorWipe(strip.Color(255, 0, 0), 200);      // Red: The blood of life 
            colorWipe(strip.Color(255, 200, 0), 200);    // Yellow: Cempazuchitl are marigolds that symbolize death. 
            break;
    case 2: checkButton();
            theaterChase(strip.Color(153, 0, 255), 200);    // Purple
            theaterChase(strip.Color(255, 0, 153), 200);    // Pink 
            theaterChase(strip.Color(127, 127, 127), 200);  // White
            theaterChase(strip.Color(200, 51, 0), 200);     // Orange 
            theaterChase(strip.Color(255, 0, 0), 200);      // Red 
            theaterChase(strip.Color(255, 200, 0), 200);    // Yellow 
            break;
    case 3: checkButton();
            rainbow(10);
            break;    
    case 4: checkButton();
            rainbowCycle(20);
            break;
    case 5: checkButton();
            theaterChaseRainbow(50);
            break;
    case 6: checkButton();
            rainbow(50);
            break;
    case 7: checkButton();
            rainbowCycle(50);
            break;
    case 8: checkButton();
            theaterChaseRainbow(100);
            break;
  }
}


void colorWipe(uint32_t c, uint8_t showSpeed) 
{
  for(uint16_t i=0; i<strip.numPixels(); i++) 
  {
    strip.setPixelColor(i, c);
    strip.show();
    delay(showSpeed);
  }
}

void theaterChase(uint32_t c, uint8_t showSpeed) 
{
  for (int j=0; j<10; j++)  //do 10 cycles of chasing
  {
    for (int q=0; q < 3; q++)
    {
      for (int i=0; i < strip.numPixels(); i=i+3) 
      {
        strip.setPixelColor(i+q, c);    //turn every third pixel on
      }
      strip.show();
      delay(showSpeed);

      for (int i=0; i < strip.numPixels(); i=i+3) 
      {
        strip.setPixelColor(i+q, 0);        //turn every third pixel off
      }
    }
  }
}

void rainbow(uint8_t showSpeed) {
  uint16_t i, j;
  for(j=0; j<256; j++) 
  {
    for(i=0; i<strip.numPixels(); i++) 
    {
      strip.setPixelColor(i, Wheel((i+j) & 255));
    }
    strip.show();

    delay(showSpeed);
  }
}

void rainbowCycle(uint8_t showSpeed) {
  uint16_t i, j;

  for(j=0; j<256*5; j++) // 5 cycles of all colors on wheel
  {
    for(i=0; i< strip.numPixels(); i++) 
    {
      strip.setPixelColor(i, Wheel(((i * 256 / strip.numPixels()) + j) & 255));
    }
    strip.show();

    delay(showSpeed);
  }
}

void theaterChaseRainbow(uint8_t showSpeed) {
  for (int j=0; j < 256; j++)     // cycle all 256 colors in the wheel
  {
    for (int q=0; q < 3; q++) 
    {
      for (int i=0; i < strip.numPixels(); i=i+3) 
      {
        strip.setPixelColor(i+q, Wheel( (i+j) % 255));    //turn every third pixel on
      }
      strip.show();

      delay(showSpeed);

      for (int i=0; i < strip.numPixels(); i=i+3) 
      {
        strip.setPixelColor(i+q, 0);        //turn every third pixel off
      }
    }
  }

// Input a value 0 to 255 to get a color value.
// The colours are a transition r - g - b - back to r.
uint32_t Wheel(byte WheelPos) {
  WheelPos = 255 - WheelPos;
  if(WheelPos < 85) 
  {
    return strip.Color(255 - WheelPos * 3, 0, WheelPos * 3);
  }
  if(WheelPos < 170) 
  {
    WheelPos -= 85;
    return strip.Color(0, WheelPos * 3, 255 - WheelPos * 3);
  }
  WheelPos -= 170;
  return strip.Color(WheelPos * 3, 255 - WheelPos * 3, 0);
}