I just need to vent and talk about this

I met this guy in January and we instantly became friends and we had feelings for each other but we both were ready for anything I was struggling with depression and just my mentality was so low that I almost killed myself he had been 6 months clean and we worked together and our job is drama filled and just horrible he ended up pushing me away and when we finically talked again he told me he relapsed for two weeks and that’s why he pushed me away and we ended up finically becoming officially boyfriend and girlfriend on a Wednesday and the next day he told everyone at work we were finally together and he was having a really shitty day that day and was upset he wasn’t gonna be able to see me that night cause I was going to see endgames with my best friend the next day was Friday he didn’t show up for work and I was extremely worried he wouldn’t answer anyone’s calls or texts I was getting yelled at about him doing a no call no show and the next day Saturday I got a call from a work friend saying he was dead and I went to his Facebook and saw his mom had made a post about it I never knew what it was like to have your world literally shatter within seconds it’s been 12 weeks since he’s been gone and I relive that moment so often and i don’t know how to stop this feeling everyone tells me he now knows how I truly felt about him but he knew I was so open about it I keep thinking there’s something I could’ve done more to keep him from relapsing and I just don’t know what to do anymore it hurts so bad