I can't keep friends for longer than 2 year, help?

I move groups all the time, I've always just drifted through friendship groups at school and college, and never really had a best friend. (M18)

I've literally just broke up with my girlfriend yesterday and it was mutual so it isn't the worst thing that's happened. This is the second time we broke up and last time was pretty serious, I took it harsh and we didn't speak for over a year due to the circumstances of it ending. I got over it and we got back together.

Last time though since we shared the same friendship group, me mainly with the guys and her with the girls when we broke up I expected the guys to have my back; they didn't, that's why I was forced to move groups. So I did I slowly moved groups and actually moved up the hierarchy and ended up with the "sporty cool guys" which is fine I like them, they're really funny.

Apart from the problem is I just realised I don't feel like I can talk to any of them about my breakup. A few of them have sat down and talked to me about their breakup or relationship problems or dealings; so it's not like we're not close. Just don't think any would care when it comes to me and now I realise I don't think anyone would care and sit down and listen to me apart from my ex and we are on good terms but I'm not going to talk about it with her, that's counter intuitive.

I just wanna know if some people are unable to make that connection and if that's why I don't stay in a single friendship group like I see almost everyone has. And if so how can I deal with this, to connect with people better and maintain close friendships until they should end.

Also do I go over board with semi-colons?