Unity Editor, Scene and Game View, suddenly very slow

Hello, I don’t exactly know what happened, but from one day to another, Unity has suddenly become very slow. Game viewing tells me is going 200+ fps, but is really going on 10-15.I searched for similar questions and some solutions consider OpenGL, or Unity Collab.
Unity Collab I tried logging out, and is not helping, and when using OpenGL, is even slower. I don’t really know what to do, but I really need the game view to run smoothly to continue the game (due to I’m fixing bugs).
Any idea what could I do. I already tried upgrading Unity and drivers too. (Now I’m using unity 2018.3.8f1)

I know this is probably a stupid answer but, here is a list of things you could do:

have you tried restarting your computer?

you could reinstall unity.

you could run the file on a different computer and see if it a problem with your computer or the file.

Okay, fixed with reinstalling Unity completly!! thank you @IchabodCraneThe3rd and @Koala_Squad!