My game is blurry after building it. [FIXED]

I updated my game and built it but when I launched the game it’s blurry. I checked and it’s not post processing and in the editor the game seems fine. The game is 2D and uses pixel art so I really don’t want it to be blurry. It looks like anti-aliasing but I have it disabled in post processing. Also I have all aspect ratios allowed but I get black bars in 16:9 aspect ratio. In the previous build it all worked fine and I just added an options menu. I would appreciate it if someone can help me with this.

6093177--662019--In Unity Editor.png
6093177--662022--In Built exe.png

Edit: I fixed the black bars by changing Project Manager > Player Resolution and Presentation > Fullscreen Mode to Exclusive Fullscreen then back to Fullscreen Window but the game is still blurry.

The problem was that I enabled Resizable Window in Player Settings and the game for some reason starts in a smaller window than my screen size and when it goes to Fullscreen it’s blurry. I made it so if you’re in fullscreen game resolution changes to your screen resolution.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class ScreenSize : MonoBehaviour
{
    public int width, height;
    private bool fullscreen = true;

    void Awake()
    {
        width = Screen.currentResolution.width;
        height = Screen.currentResolution.height;
    }

    void Update()
    {
        if (fullscreen)
        {
            Screen.fullScreenMode = FullScreenMode.FullScreenWindow;
            Screen.SetResolution(width, height, true);
        }
        else Screen.fullScreenMode = FullScreenMode.Windowed;

        if (Input.GetKeyDown(KeyCode.F11)) fullscreen = !fullscreen;
    }
}