Brush turns into eraser photoshop 2021

[DGorsh19]

So I'm having issues with my brush tool in Photoshop 2021 and it's getting very annoying now. So im on a layer mask and im trying to paint in black on my layer mask. I set my opacity and my flow settings and I tried painting but it seemed like my brush settings weren't working. I opened my history panel and instead of the brush being used, for some reason my brush kept on switching to the eraser whenever a made a brushstroke. I have the brush tool selected and when I go to make a brushstroke, it says in my history panel that I am instead using the eraser. Is anyone else having this problem? I tried uninstalling Photoshop and re-installing it, shutting down the program and re-opening it and I'm still having the same problem. 

[DGorsh19]

This is what I'm talking about. Also when I click to make a brush stroke my brush will randomly change sizes. Is this a bug with photoshop or something I set wrong? Cause I don't know anymore. 

[melissapiccone]

Reset preferences. Are you using a tablet or a mouse? Your screenshot is not complete-  I can't see the bottom of your history panel nor your layers. 

[DGorsh19]

I use a tablet on my MacBook Pro. I never had any issues previously with my tablet other than a few days ago. I am using an XP Pen Artist Pro 13.3. I also recently updated my laptop to Big Sur and so that is what I thought he problem was but I uninstalled and re-installed photoshop and have had the same issues.