I can relate. I don't know how I would function without Adderall and caffeine. Stimulants alone don't help me though. Wellbutrin, an antidepressant, seem's to work well for the depression. You are 22 years old so you still have some changing to do and it can still get better, trust me. Im 25 and I was just like you are now at 22. You say you've tried therapy but did you stick with a treatment plan? There are so many doctors who could help you. I know it seem's impossible to find the motivation to do just about anything when you feel like this though. I've felt like a complete waste of space and hopeless at ever achieving anything productive in life. I still feel that way sometimes.
Try to find something that really stick's with you. Something your good at. I found music and focused all of that pain into playing the guitar and writing.

If I can get better, so can you. I didn't leave my house for almost 3 years because of depression and anxiety. I felt worthless. But sticking with a trusted therapist who understand's you helps SO MUCH.