So my boyfriend and I argue but love each other to death and the other week he stopped talking to me and wouldn't reply to my messages so I finally called him after 4 days and said he wants a break to pull his head in and fix himself. What does this mean for our relationship?

It means give things a chance to calm down and talk rationally later. Do as he asked and leave him alone to do so.

You need to give him some time to thinks things through.

One he can't be playing a game with u. Or some other stuff can be going on with him.