I think a lot of it is figuring out your needs and then figuring out how to get those needs met. Sometimes the problem is isolation, your need is social interaction, and to get those needs met you start talking to people, for example. Many times there are multiple problems going on so the answer is much more complex, and you need to work on one thing at a time. You're not doomed forever. Mental health "treatment" is extremely flawed right now and many people will never find an adequate therapist/psychiatrist/psychologist.

The idea of getting some books from reputable doctors and therapists is a good one. I don't know what your major concerns are, but educate, educate, educate yourself. A helpful book/tool I have is called WRAP (Wellness Recovery Action Plan). You come up with stuff to do every day to take care of yourself and stuff to do at different stages of symptoms.

I don't think you're doomed. You need to find some hope and figure out how to get where you need to be.