From my perspective, this sounds like depression. I was diagnosed with it four years back. I knew it from those things that you identified...distanced from others, crying for no reason, unstoppable feelings of guilt, insomnia, constantly thinking about not being alive, and simply a down mood...In my case, therapy and medication helped in the past; it's helping again as the depression remitted for about a year. It's not a life sentence as mine was exacerbated by an unemployment situation. I hope that this helps, and hope that you can find some help through the supportive folks here on Psych Central.