I'm hoping somebody on here is a linux user. I need some help.

Today I logged into Gos which is ubuntu based and my screen resolution had changed to a higher resolution. When I went to go change it the screen changed to where I can't see what I'm doing.

I'm trying to figure out how I could change to screen resolution within the terminal. I can still see the log in screen and change the session to failsafe terminal. I just can't find or figure out the correct syntax to change to screen resolution. I am somewhat a novice to linux, and enjoying more than windows.

If anybody can help or point me in the right direction I would be most appreciated and would be in debt to you, cause I don't want to reinstall it to fix it. Thank you.