Whats going on threw his head? ex bf..?

Just be friends with him for now, try and move on (seeing other people if someone comes along) and see what happens. You haven't said anything about the reasons for the two of you breaking up or anything, so I can't begin to try and ume what is going on in his head. If you want to know, then you will have to ask him. If he has told you he misses you, then its a definite indication that he still has feelings for you. But like you said, he could still be the same a month away. The thing is, you both clearly still like each other, so if a second chance comes up, you should take it. I have before, and in your situation i would.