It's not healthy at ALL!
She's gonna drive you crazy...It must be hard for you.
Communication is KEY, and it seems she doesn't like to talk about things, that's really bad, you should always be able to tell your significant other things that bother you!
After reading this and your other post, I believe your going trough a hard time now, wondering WHY is this happening now?
Well remember people start showing their true colors in time! And after 4 years of being together you probably don't know her how you thought u did.
My advice-TALK to her, sit her down, tie her up jk LOL, do whatever you have to do and tell her how you're feeling and what can u both do to make things better and not fight so much! It will surely work =)
Good Luck
God never closes a door without opening another one!