Volunteering sounds like a great idea. I think that going to work is a great goal but one that can be broken down into smaller steps. For example, how well can you leave the house? Go to public places? Interact with strangers? If you struggle with these, you can work on them in small ways before you ever have a job. Go out in public, go to a store, stay there for a while, eventually you might interact with strangers, ask questions, even start a conversation.
Anything that you struggle with in a job can be practiced outside the job setting in an easier and less stressful way.

I like David Carbonell's The Panic Attacks Workbook. It goes into step by step procedures for dealing with panic. Good luck