You are so down right now and my heart breaks for you. I have been in this position of feeling like "a waste of space." The only thing that helped pick me up is finding some shred of something to be grateful for. I then tried to find something else to be grateful for and in time I found that gratitude changed my inner thoughts and life was so much better then my negative talk was telling me. Try it. Find anything to be grateful for.
I am grateful today because I have good health. I am not in a hospital sick and bed ridden. I am grateful today because I have a computer to reach out to people. I am grateful for . . .
It isn't easy at first but you can change your thinking and you will realize you are VERY important to this world and there are many people that are effected by your presence. Wishing you peace today.