There is no Vcc pin on a genuine Arduino. The are 3.3V, 5V, and Vin pins.
You don't have to read the schematics to see what each are for. Just the description of the board tells you
Vin: The input voltage to the Arduino/Genuino board when it's using an external power source (as opposed to 5 volts from the USB connection or other regulated power source). You can supply voltage through this pin, or, if supplying voltage via the power jack, access it through this pin.
5V: This pin outputs a regulated 5V from the regulator on the board. The board can be supplied with power either from the DC power jack (7 - 12V), the USB connector (5V), or the VIN pin of the board (7-12V). Supplying voltage via the 5V or 3.3V pins bypasses the regulator, and can damage your board. We don't advise it.
3V3: A 3.3 volt supply generated by the on-board regulator. Maximum current draw is 50 mA.
GND: Ground pins.
As you see, using the Vin pin or the barrel jack does the same thing. Both go through the regulator.
You can use the barrel jack to power the Arduino or is you are careful you can use the 5V pin. But if you use the barrel jack for power, your CANNOT use the 5V power to power anything else. The regulator between the barrel jack and the 5V pin has just enough to run the Arduino. Attaching anything to the 5V when using the barrel jack (or Vin in pin) causes the EXACT issues you have described.
If I was standing next to you, I would have reached over and yanked out the red wire connected to the 5V pin, 10 posts back.
Your power supply, which is 5V, should be connected DIRECTLY to both the Arduino and the display. The daisy chain you have, power supply to Arduino and the Arduino to the display, is causing your problem.