How to make projectiles shoot towards mouse

I started Unity and C# about a week ago and have been building small projects to get started. I want to learn how to make a 2D shooter and have made some progress. I can successfully instantiate the bullet and add some force to it (seemingly) in the direction of my mouse. The problem is that there seems to be a constant force up and right. Depending on where my mouse is, the bullets move slower. The only way I can get the bullets to travel left is if the mouse is in the very bottom left of the screen. Here is the script in question:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class BulletTracker : MonoBehaviour
 {
     public float moveSpeed;
     private bool hasShot = false;
     public Rigidbody2D rb;
     public GameObject bulletSpawn;
     
     void Update() {
         if (!hasShot)
             rb.AddForce(Input.mousePosition * moveSpeed);
             hasShot = true;
     }
 }

I know this is probably incredibly inefficient and could be done easier, but for now I am just getting the hang of the language. The variable bulletSpawn is the empty object in front of my character where the bullets spawn. When I spawn the bullets without this script active, the bullets just fall to the ground, so I think the problem must be here somewhere. If anyone could help I would really appreciate it. Thanks!