Slow your roll.

You're right that he fucked up with the break, and yes, he's jealous. However, I'm inclined to believe that the reasons for OP initiating the break came from a positive place.

The ex in this situation took advantage of that as a free pass at another guy she's probably long considered her "plan B":

She tells me she kissed him the day before, and she needed some time to think...she needed to be single for a while and that he was still just a friend.

Do you make out randomly with your friends? She then drops this gem:

She says she didn’t move on and misses me.

Interesting, especially considering her non-contact and quick turn around to kissing another guy.

About two and a half weeks in, her friend from college visits. The entire time he’s here I can’t get a hold of her once

You don't find this a little suspicious at all? This is probably the guy she's been bitching to about OP; he just swooped in and white knighted the shit out of the situation.