Arduino Coding Issue: 2 sections not working when combined

I'm using an Arduino Uno and trying to code together 2 parts of a school project. Both parts work fine separately but when combined, only part 1 works. Part 1: Involves 1 button switch, 2 LEDs where one stays on and one stays off, the button changes which is on or off. Part 2: Servo controlled by potentiometer

I've determined that the servo only ends up working when the button is pressed down, which shouldn't be happening, the potentiometer/servo code shouldn't be dependent on the code for the LEDs. I'm definitely a beginner at this and don't understand a lot of what the code is doing, so forgive me for any redundancies. Any help is much appreciated.

#include <Servo.h>
Servo myServo;
int const potPin = A0;
int potVal;
int angle;
int switchState;
int lastSwitchState = 0;
const int bluePin = 3;
const int yellowPin = 4;
const int button = 2;
int bluelight = LOW;
int yellowlight = HIGH;

void setup(){
  pinMode(bluePin, OUTPUT); //blue LED
  pinMode(yellowPin, OUTPUT); //yellow LED
  pinMode(button, INPUT); //switch
  myServo.attach(9);
  Serial.begin(9600);
}
void loop(){
  // PART 1 - this is the only part that seems to be working now?
  switchState = digitalRead(button);
  while (digitalRead(button)==LOW); 
  if (digitalRead(button)==LOW){ 
  bluelight=!bluelight;
    digitalWrite(bluePin, bluelight);
    digitalWrite(yellowPin, yellowlight);
  }
  else{
  if (switchState=!lastSwitchState) {
    yellowlight=!yellowlight;
    bluelight=!bluelight;
  digitalWrite(yellowPin, yellowlight);
  digitalWrite(bluePin, bluelight);
  }
  }
  // PART 2 - Only works when button is pressed? 
    potVal = analogRead(potPin);
  Serial.print("potVal: ");
  Serial.print(potVal);
  angle = map(potVal, 0, 1023, 0, 179);
  Serial.print(", angle: ");
  Serial.println(angle);
  myServo.write(angle);

  delay(250); //wait for a quarter second
  }