I need closure with my ex-boyfriend?

My boyfriend and I had been together for a year and 1/2. I broke-up with him because I felt his heart was not in it. He said it wasn't true, declared his love and commitment to me, then , about a week after that, he just ended it. I have not seen him for 3 weeks and not had any contact with him for 2 weeks. I emailed him a few weeks ago and told him I would like to talk to him and told him I really needed to know what went wrong with us, why he was so ready to commit, and then - boom - it was gone.. but he will not talk to me, he will not email me, and I really feel like I need closure. I think I deserve that after a year 1/2. It feels like a huge part of me is gone. We met on the internet personals and on a hunch, I took a peek about a week ago and he has a very elaborate dating profile up. I'm just in disebelief that he is so ready to move on again and doesn't even want to end this civilly. Your thoughts?