I had a friend od in August of last year and I think it was suicide. He also lived close by and had been wanting to hang out, but like you, I'm not very social sometimes and I was recovering from a major surgery. He and his girl friend were in financial straights but I don't know of any other problems he had. And he also wasn't an intravenous drug user. His girl friend called us after calling 911and we got there as they called it and I was there to answer questions for the coroner to try and spare his girl from dealing with it. I don't have much to offer other then sympathy. And I'm sincere about that. Regardless of cause, there is sudden hole in you and the circumstances make it worse. I also felt guilt, and still do, but if there was no indication thaf he was in danger, then you shouldn't feel responsible. My friend was a close friend, and was also the first of my friends to die. I came to terms with it to a degree but I mourn his loss to this day but it gradually gets better.