I'm so sorry things got to that point. I think the advice above is good. I actually got involved with volunteer work during a time when I was at a very low point and it really helped to lift my spirits. It was a really inspiring and awesome experience for me. It is amazing how having a positive effect on someone else can have a positive effect on you. I would suggest trying to stay as productive as possible. Don't give yourself too much time to entertain negative thoughts. Don't allow your mind to remain idle for too long. The more focus and energy you put into bringing forth positive results, the less space and time negative thoughts have to occupy your mind. I would suggest finding someone to talk to as well. There is nothing wrong with seeking professional help. I have done this myself and it has helped save my life. There are suicide prevention hotlines. You do deserve to exist. Your life has purpose and value. Hang in there.
