Has this happened with any of you ever?

Nowadays I've been acting very weird..behaving selfishlessly even with my loved ones..and then feeling extremely guilty later on.. Even doing some of the socially unacceptable things and then feeling like a weirdo and then feeling depressed about it.. Even saying things which I shouldn't and then feeling guilty about it the next minute.
I can't understand why this is happening with me.
I've never behaved this way before. I'm feeling like a nobody right now.
Why does this happen?
Has this happened with any of you ever?