You *never* have to feel guilty of unloading stuff on me. I know from experience this is something that's hard to tell someone, but I hope you give me the opportunity to show you instead.
Have you considered volunteering somewhere? I know how intimidating that sounds, but, when I was in your position, I let someone talk me into it, and it helped a lot more than I thought it could have. For me, it was a Soup Kitchen, but anything you can think of that might help you feel valid for even a minute will help in the long run. And please do not forget what FCG said--I can tell you from personal experience things are MASSIVELY easier with a support community, and you have at least three people here wanting to be that for you.
Regarding helping others, yeah, your inner you is going to try to stomp you to the ground at every attempt just like mine did. However, if you keep at it with support, that inner you will slowly weaken until you can regularly defeat him on your own. You are not alone anymore.