My ex did all the same stuff right before he flew to New York to go hook up with some other chick. He told her in emails that we were living together, but only because I needed his financial support (which was an utter lie - I paid for everything). He was also super sweet to me right before he left. He spent extra time with me and brought me presents.......then proceeded to turn his phone off for the entire week he was away. Cheating bastard.
The fact that he already told her in an email that he loves her and has been looking everywhere for her tells me he's definitely not over her, and is not just going to let this go. Maybe he'll dangle you both on the end of the hook for awhile while he decides which one he'd rather be with. If I were you I'd make the decision for him.
Put it this way - he's already cheating on you, emotionally. He's told this other girl he loves her and is purposely still holding onto her photos. That would be all I needed to walk out the door. Nowadays, anyway.
