Platformer problems

I am currently in the process of developing my first platformer, and I've decided that I want to bake my own acceleration and deceleration for movement instead of using unity's wonky physics. ........................................................................................................................................................... This has brought up two roadblocks, one being that my character will just clip through objects like walls to jump over or off of, and the other is that if I try to switch directions while decelerating, my character will turn around, but it won't change directions and my acceleration will bypass the limit I set for it (in layman's, it zooms backwards). ................................................................................................................................................................. I need help fixing this and can describe any of the functions of the variables if asked. There is no physics material on my character, and I am using physics for the jump. ............................................................................................................................................................. All of the variables are defined in the unity editor for easier tweaking except for currentSpeed, jumpCount, FallTime and canJump, which I have serialized so I can observe them during testing.

 using System.Collections;

using System.Collections.Generic; using UnityEngine;

public class PlayerControls : MonoBehaviour { //walk Vars [SerializeField] float currentSpeed; [SerializeField] float maxSpeed; [SerializeField] float jumpstart; [SerializeField] float acceleration; [SerializeField] float deceleraton; int isFlip = 1; Vector2 newPos; Quaternion flip;

 //jump Vars 
 [SerializeField] public int jumpCount;
 [SerializeField] public int jumpCountMax;
 [SerializeField] public float jumpVel;
 [SerializeField] public float fallMulti;
 [SerializeField] public float shortMulti;
 [SerializeField] public float fallTime;
 [SerializeField] public float coyoteTime;
 [SerializeField] bool canJump = true;
 [SerializeField] bool didJump;

 //references
 Rigidbody2D rb;

 private void Awake() {
     rb = GetComponent<Rigidbody2D>();
 }

 //walk Functions
 private void speedCalc() {
     currentSpeed += jumpstart * isFlip;
     if (currentSpeed * isFlip >= maxSpeed) {
         currentSpeed = maxSpeed * isFlip;
     }
     else {
         currentSpeed = (currentSpeed * acceleration);
     }
 }

 private void Start() {
     currentSpeed = 0;
 }

 private void Update() {
     //calculate coyote time
     if (fallTime == coyoteTime) {
         if (didJump == false) {
             jumpCount += 1;
         }
     }
     if (jumpCount >= jumpCountMax) {
         canJump = false;
     } else {
         canJump = true;
     }
     if (rb.velocity.y == 0) {
         jumpCount = 0;
         didJump = false;
     }

     //calculate isFlip
     if (Input.GetButton("Right")) {
         flip = Quaternion.Euler(0, 0, 0);
         transform.rotation = flip;
         isFlip = 1;
     } else if (Input.GetButton("Left")) {
         flip = Quaternion.Euler(0, 180, 0);
         transform.rotation = flip;
         isFlip = -1;
     }

     //calculate acceleration & deceleration
     if (!Input.GetButton("Right") && !Input.GetButton("Left")) {
         if (currentSpeed * isFlip <= jumpstart) {
             currentSpeed = 0;
         } else {
             currentSpeed = (currentSpeed / deceleraton);
         }
     } else {
         speedCalc();
     }

     //implement falling and dyanamic jumping
     if (rb.velocity.y < 0) {
         fallTime += 1;
         rb.velocity += Vector2.up * Physics2D.gravity * (fallMulti - 1) * Time.deltaTime;
     } else if (rb.velocity.y == 0) {
         fallTime = 0;
     }  else if (rb.velocity.y > 0 && !Input.GetButton("Jump")) {
         rb.velocity += Vector2.up * Physics2D.gravity * (shortMulti - 1) * Time.deltaTime;
     }

     //execute jump
     if (Input.GetButtonDown("Jump") && canJump == true) {
         didJump = true;
         rb.velocity = Vector2.up * jumpVel;
         jumpCount += 1;
     }

     //move character position
     newPos = new Vector2(transform.position.x + currentSpeed, transform.position.y);
     transform.position = newPos;
 }

}