Stack overflow caused by "while" loops

I'm very new to coding, so forgive me if I'm missing something obvious here.

I'm trying to make a system where if the 2D player suddenly changes direction with a certain amount of velocity, it hops them back a bit in the opposite direction, cancels out their velocity, and increases drag for two seconds.

However, every timed iteration I've done trying to get the drag to increase has resulted in instant crashed the moment the function is called into action.

Is there some infinite loop or contradiction I'm missing here? Maybe I have artist's eye and it's right in front of me.

Code (please don't laugh):

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using System;
 
 public class PlayerMovement : MonoBehaviour
 {
     public float moveSpeed = 5f;
     public Rigidbody2D rb;
     public Vector3 velocity = new Vector3(0f/*x*/, 0f/*y*/, 0f/*z*/);
     public Vector2 movement;
     public Vector2 position;
     public int time = 0;
     public int slowtime = 0;
     public int slowtimer = 2;
     public float bumbdecrease = 0f;
     public float bumbdash = 1.0f;
 
     void Start ()
     {
         StartCoroutine( Example() );
     }
 
     void Update()
     {
         movement.x = Input.GetAxisRaw("Horizontal");
         movement.y = Input.GetAxisRaw("Vertical");
     }
 
     IEnumerator Example ()
     {
         yield return new WaitForSecondsRealtime(1);
         time += 1;
     }
 
     void FixedUpdate ()
     {
         velocity = rb.velocity;
         position = rb.position;
         rb.AddForce(movement.normalized);
 
         if (velocity.x > 6 | velocity.x < -6 | velocity.y > 6 | velocity.y < -6)
         {
             if (velocity.x > 6 & movement.x < 0)
             {
                 rb.inertia = 0;
                 velocity.x = -(velocity.x * bumbdecrease);
                 rb.velocity = velocity;
                 position.x = position.x - bumbdash;
                 rb.position = position;
 
                 slowtime = (time + slowtimer);
 
                 do
                 {
                     rb.drag = 12;
                 } while (slowtime > time);
 
                 rb.drag = 6;
             }
             else if (velocity.x < -6 & movement.x > 0)
             {
                 rb.inertia = 0;
                 velocity.x = Math.Abs(velocity.x * bumbdecrease);
                 rb.velocity = velocity;
                 position.x = position.x + bumbdash;
                 rb.position = position;
 
                 slowtime = (time + slowtimer);
 
                 do
                 {
                     rb.drag = 12;
                 } while (slowtime > time);
 
                 rb.drag = 6;
 
             }
 
             if (velocity.y > 3 & movement.y < 0)
             {
                 rb.inertia = 0;
                 velocity.y = -(velocity.y * bumbdecrease);
                 rb.velocity = velocity;
                 position.y = position.y - bumbdash;
                 rb.position = position;
 
                 slowtime = (time + slowtimer);
 
                 do
                 {
                     rb.drag = 12;
                 } while (slowtime > time);
 
                 rb.drag = 6;
             }
             else if (velocity.y < -3 & movement.y > 0)
             {
                 rb.inertia = 0;
                 velocity.y = Math.Abs(velocity.y * bumbdecrease);
                 rb.velocity = velocity;
                 position.y = position.y + bumbdash;
                 rb.position = position;
 
                 slowtime = (time + slowtimer);
 
                 do
                 {
                     rb.drag = 12;
                 } while (slowtime > time);
 
                 rb.drag = 6;
 
             }
         }
     }
 
 }