Really hurt

I'm drunk writing. I left my boyfriend about a month ago. And need some convincing that it was the right thing to do. We were doing long distance. Me in Malaysia, he in Hong Kong. We met in London while we were still studying there. We had originally plan to move to London together as I wanted to work/do my masters there. And he is from England. Ever since we got into a relationship I just felt like he didn't really appreciate me. He met a couple of guys that played games so he joined them. He would Skype me less because he always just wanted to spend time with them. And he was less loving than he was when we were in London. He even admitted he wasn't giving his all anymore in the relationship and doesn't know why. He even keep things from me like how much he actually smokes, or when a girl texts him. I feel like throughout the relationship he was just there but not really doing anything, not investing himself. And when I left, he didn't even stop me. No hesitation. Just let me go. It just really hurts. He used to put in so much effort when he was trying to get me. And once he did, everything stopped. I texted him saying we could be friends this afternoon, and he admitted to just ignoring it all day. Them said he didn't have time to talk to me because he had to go out for dinner I just feel so heartbroken right now.