I personally don't want to rain on your parade that is about your taking all the blame here but I will be honest, and wonder about his motives in the first place with his ex, so I really don't blame you for getting upset.

Who goes out of their way to connect with exes, accept gifts and keeps in touch with them like that? You are not all that far off when you say you were suspicious. IMO, I think that's weird. For me, for my current gf or SO's benefit I would steer clear of exes, period. Fact that he was so quick to want to take a break also makes me question him. Instead of being so angry as to actually push you away like this he should WANT to give you security.

He doesn't want to hear it, he is making you out to be a terrible person for being jealous? He should understand that this would cause a lot of problems with a great number of women out there or men.. it really bothers me that he's making you feel so bad for feeling insecure.

I can't tell you what to do to get him back. I can't in good conscience suggest that but that you just let it go move on. That is just my opinion based on your post.. I could be wrong..