Servo and DC motor working at the same time

Hi! I need a servo and a DC motor working at the same time, each one controlled by a potentiometer (and a mosfet for the DC motor), as you can see in the picture that I attached.

If I move just the servo, it works fine, but when I switch on the DC motor, the servo goes to 0º automatically untill I stop the DC motor.

I simulated it on 123D circuits and it works. I read on other forum that it is impossible to use pin 9 and 10 for PWM when you´re using the servo library, so I didn´t use those, I tried all the pin combinations but it doesn´t work well.

I hope you can help me. Thanks for your time

#include <Servo.h>
Servo myServo;

int const potPin = A5; // analog pin used to connect the potentiometer
int potVal;  // variable to read the value from the analog pin
int angle;

const int potMotPin = A0;
const int motorPin = 11;
const int servoPin = 9;
int potValor;
int ajusteVel;

void setup() {
  pinMode(motorPin, OUTPUT);
  pinMode (potMotPin, INPUT);

  myServo.attach(servoPin);
  Serial.begin(9600);


}

void loop() {
  potValor = analogRead(potMotPin);
  Serial.println(potValor);

  ajusteVel = potValor / 4;
  delay(5);
  analogWrite(motorPin, ajusteVel);

  potVal = analogRead(potPin); // read the value of the potentiometer
  // print out the value to the serial monitor
  Serial.print("potVal: ");
  Serial.print(potVal);

  // scale the numbers from the pot
  angle = map(potVal, 0, 1023, 0, 179);

  // print out the angle for the servo motor
  Serial.print(", angle: ");
  Serial.println(angle);

  // set the servo position
  myServo.write(angle);

  // wait for the servo to get there
  delay(15);

}

The PP3 type of 9v battery is completely unsuitable. It can't provide enough current. Use 6xAA cells if you need 9v.

DON'T power the motor OR the servo from the Arduino 5v pin. Give them their own power supply with a common GND with the Arduino.

...R