Well I can empathize with your reaction to his pulling away, because he's totally being a selfish douche, projecting his ex-g/f's behavior and personality on to you, as though you're going to treat him the way she did (you're not, of course).

He sounds so immature. No one is perfect. But no one should have to compete with an ex, in their current relationship. If that starts happening, I take that as a red flag that the guy I'm with isn't emotionally available and then I have a choice: I can dump him, or I can stay and allow myself to be completely taken advantage of and emotionally abused. I've been where you're at. It's not a pleasant place to be.

Now that I want to put myself first, I won't give any guy a chance if he shows me he's going to be a douche-bag.