A friend's struggle

First of all, this website is mean. It calls me names. I may look funny but it doesn't have to call me a clown.

All jokes aside, I have a friend I'm a little worried about at times.
He's a hard worker. He works nights on and off with the occasional morning/afternoon shifts after the same day he worked nights. He doesn't have a physical demanding job, but I feel that he neglects his sleep a little.
He's told me how exhausted he gets and how he often gets discouraged from activities because of his exhaustion.

Anyways, he's an ex-addict. He's been on most drugs according to him. I know this is something he's struggled with and I feel like he could easily fall back into it. He's admitted that its been tough in him recently and by the way it seems, he's desperate to relieve himself of some of his responsibilities.

To add more of why I'm worried, he's also quite a bit conflicted with his sexuality I feel. I talked to him about his roommate and joked about him being gay. His response was "he might be, but I'm 100% straight." Which I felt was odd. It was then that I felt like I would come out as bi-curious to him because although he proclaimed himself as straight, he didn't seem at all bothered or worried that his roommate might be gay. It was an interesting conversation because eventually he admitted to being bi-curious himself. I felt like he really opened up to me and told me things that he hasn't even told his friends that he's known for years about (I've only known him about 6 months so far, and this was a month or so ago). Anyways, in this conversation I found out that he's had one gay experience, has always wanted to have gay sex but is not comfortable with bottoming, and sometimes wants to have a relationship with guys. The thing that held him back was how he'd be accepted. He knows some friends would be okay with him liking guys but he'd be afraid to push anyone away that wasn't comfortable with it. He also admitted to me that he had a very traumatic incident with his father when he was young that he feels has scared him into accepting and even becoming comfortable with himself. I wouldn't feel right saying exactly what happened because I know for a fact that nobody knows what happened, but I can tell its something that's scared him into the closet at least a little. His sexuality seems to fluctuate too. At first it was that he preferred guys, then he seemed to prefer girls. I do feel though, that he said he preferred girls after all because he was uncomfortable with the thought of being out at all. I worry that he's suppressing how he feels about his sexuality at times.

Anyways, I felt we were close. I felt like he was opening up to me and I don't feel like he has many people to open up to like that.
It was until I started to bug him (I think that's what it was, anyways) that he's kinda become distant. Maybe he just needed someone around that he could tell his secrets to. Which I don't mind at all. I just feel like I became a little attached to our friendship and might have made him uncomfortable.

I've since had a falling out with a mutual friend and it seems like he's taken their side in the argument. At least he's been closer to then, talking to them a lot more often, and doesn't even bother talking to me anymore.

I want to reach out to him and try to salvage our friendship a bit because it was nice to have someone confide in me. Plus I'm worried about him.
Does anyone have any idea how I can go about this? I know he's not necessarily mad at me or purposely picking a side through this argument, but I feel like he's a good friend that I might lose if I don't try to reach out to him. I just don't know what to say to him.