2D Tile Based collision problem

Okay, so basically I'm trying to make a game similar to the early Ultima's (I-V) I tried to implement a basic code I found on the forums and it works Perfectly! except for one big problem; collisions aren't being detected on the -x and +y planes (Left and Up?) and the collision boxes for the player and the walls seem to get stuck in each other; rendering my player completely stuck, with restarting being the only solution: I've tried plenty of fixes such as changing the material of the wall colliders to set the friction to 0, or using an edge collider instead of a boxcollider2d but none of these have worked; help is greatly appreciated. My Code:

 using UnityEngine;
 using UnityEngine.UI;
 using UnityEngine.SceneManagement;
 using System.Collections;
 
 public class Movementy : MonoBehaviour
 {
 
     public float speed = 2.0f;
     Vector3 pos;
     Vector3 old;
     Transform tr;
 
     void Start()
     {
         pos = transform.position;
         tr = transform;
     }
 
     void FixedUpdate()
     {
         if (Input.GetKey(KeyCode.UpArrow) && tr.position == pos)
         {
             pos += (Vector3.up) / 1;
         }
         else if (Input.GetKey(KeyCode.RightArrow) && tr.position == pos)
         {
             pos += (Vector3.right) / 1;
         }
         else if (Input.GetKey(KeyCode.DownArrow) && tr.position == pos)
         {
             pos += (Vector3.down) / 1;
         }
         else if (Input.GetKey(KeyCode.LeftArrow) && tr.position == pos)
         {
             pos += (Vector3.left) / 1;
         }
 
         transform.position = Vector3.MoveTowards(transform.position, pos, Time.deltaTime * speed);
     }
 
     void OnCollisionEnter2D()
     {
         float x = transform.position.x;
         float y = transform.position.y;
         float z = transform.position.z;
 
         if ((int)(x + 0.5) > (int)x && x > 0)
             x = (int)x + 0.5f;
         else if ((int)(x - 0.5) < (int)x && x < 0)
             x = (int)x - 0.5f;
         else
             x = (int)x;
 
         if ((int)(y + 0.5) > (int)y && y > 0)
             y = (int)y + 0.5f;
         else if ((int)(y - 0.5) < (int)y && y < 0)
             y = (int)y - 0.5f;
         else
             y = (int)y;
 
         z = 0f;
 
         Vector3 away = new Vector3(x, y, z);
         pos = away;
 
     }
 }