Lifting box 2D C#

Hello guys, I have a big problem with my C# script, which i use for lifting a box up and down (after that, i want to use this script for all liftable objects). I have 4 problems.

     1) If I collide with box, the collision stay even if player is far away (I know, is’t because I have OnTriggerStay2D, but if i use OnTriggerEnter 2D, nothing was happened)

     2) If i lift the box up and after that i want to lift the box on another object, the object will simply make way on left or right and the box will stop on the floor.

     3) The script lift the box only if the box gravity is off, because if i turned it, then the box slowly fall down

     4) When i go with the box and then stoped, the box move farther away (if the box is lifted up)

Thanks for your answers. Yours sincerely GunSpawn. P.S.: The script is here

 using UnityEngine;
 using System.Collections;
 
 public class MoveWithItems : MonoBehaviour
 {
 public bool isHolding = false;
 public bool isItem = false;
 public GameObject box;
 public GameObject player;
 
 private int numClick = 0;
 
 void Start ()
 {
 
 }
 
 void Update ()
 {
 if(Input.GetKeyDown(KeyCode.E))
 {
 isHolding = true;
 if(isHolding == true && isItem == true)
 {
 box.transform.position = new Vector3(box.transform.position.x, box.transform.position.y + 3);
 numClick += 1;
 }
 if(numClick == 2)
 {
 box.transform.position = new Vector3(box.transform.position.x, box.transform.position.y – 6);
 numClick = 0;
 }
 }
 
 }
 
 void OnTriggerStay2D (Collider2D col)
 {
 if (col.gameObject.CompareTag(“Holded items”))
 {
 isItem = true;
 if(isHolding == true)
 {
 col.transform.parent = player.transform;
 
 }
 if(numClick == 0)
 {
 col.transform.parent = null;
 isHolding = false;
 }
 }
 }
 }