Brush turns into eraser photoshop 2021

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.