I'm so sorry that you're feeling like this. I'm glad that you're here though! You're not worthless i can assure you! You have value, and you could NEVER be replaced. You are wanted, and accepted here.

There also could be other options, or options that could add to what you have now(treatment wise). if you're an animal lover, there are therapies involving animals that might be helpful. (ex. Horse therapy, and hospital building pet therapy).