Hey there so_punk_rock!
Keep on going, you are worthwhile, you do have value and things can change for the better!
Have you ever considered volunteering? I do some volunteering and it does help my self esteem knowing that I am at least sometimes helping out in some small way. It also gives me a chance to chat to other people as I tend to be quite a loner otherwise.
I found opportunities for volunteering just by googling my local area. One place I go to pays my petrol costs and I get a very nice meal (with loads of leftovers I get to take home) cooked free for me each week

What's to lose!!!