Top Down 2D movement issue

Hello, I got a problem, I think it's no about code but with Unity, but for certainty I put here code. So my problem is when I start a game, the player start move backward (fall down it look like, yes and fixed by checking kinematics but I know the kinematic can be off and it should be working) and my bullets have more force when I'm shooting downward, I don't understand it, why it is doing this. Thanks for help.

 using UnityEngine;
 using System.Collections;
 
 public class PlayerMovement : MonoBehaviour {
 
     public float walkSpeed;
     private float curSpeed;
     public float maxSpeed;
     public float sprintSpeed;
     public float speed;
     public Rigidbody2D rg2d;
     public Rigidbody2D bullet;
     //public Transform bulletSpawn;
     public float bulletSpeed;
     public float xValue;
     public float yValue;
     //private CharacterStat plStat;
     
     void Start()
     {
         //plStat = GetComponent<CharacterStat>();
 
         //walkSpeed = (float)(plStat.Speed + (plStat.Agility/5));
         walkSpeed = speed;
         sprintSpeed = walkSpeed + (walkSpeed / 2);
         
     }
     
     void FixedUpdate()
     {
         curSpeed = walkSpeed;
         maxSpeed = curSpeed * 2;
         if (Input.GetMouseButton (0)) {
             Rigidbody2D bPrefab = Instantiate(bullet, new Vector3(transform.position.x + xValue, transform.position.y + yValue, transform.position.z), Quaternion.identity) as Rigidbody2D;
             
             bPrefab.GetComponent<Rigidbody2D>().AddForce(transform.up * bulletSpeed);
         }
         // Move senteces
         rg2d.velocity = new Vector2(Mathf.Lerp(0, Input.GetAxis("Horizontal")* curSpeed, 0.8f),
                                            Mathf.Lerp(0, Input.GetAxis("Vertical")* curSpeed, 0.8f));
 
 
         var MousePos = Camera.main.ScreenToWorldPoint (Input.mousePosition);
         Quaternion qot = Quaternion.LookRotation (transform.position - MousePos, Vector3.forward);
         transform.rotation = qot;
     }
 }