Is my best friend abusing me?

We’ve been best friends for two years now. He’s a boy, I’m a girl, it started with him having a crush on me. That ended shortly and we became great friends. This year though, I feel like he’s been getting obsessed with being popular and to hell with all that crap. But when he’s online he’s really nice. Anyways, that’s just a history. I know a ton of his secrets. So my sister has this huge somewhat medical issue that has been affecting me and my whole family and it’s very sad. So, I told him a little bit about it. He was very sympathetic and what not. Next thing I know my half friend half worst enemy tells me that he told her. I confront him about this. He says she begged, she said she didn’t. But this is severely serious. And he’s just been trying to make me feel guilty about how I’m mad at him about it. He hasn’t said sorry. It was his birthday last week and I got him a present. I tell him to pick it up and he’s never gotten around to it. I tell him we need to talk and he says ya, but is lazy and doesn’t do anything about it. So I have to be proactive. So I sent him a text about how upset I was and he just sent me an email saying he would be antisocial with me. How come when I need him most he’s acting like this? All I ask is that he make an attempt to talk to me, and apologize. But now he’s been making me feel like I’m the one who needs to apologize. HELP!