My son struggles with anxiety. I dream of him someday overcoming his doubts, fears and blame and doing something like you are doing.
Just keep asking yourself, "what's the worst thing that can happen?" Run it all the way to its ultimate end. Even if you can push it all the way to, "I could die" (probably unlikely) then try to do it anyway. There are no guarantees or promises in life for anyone.
I have to believe that every time you give your anxiety the finger and push out that envelope with a successful experience, your world just got wider and brighter.
I have only had anxiety attacks for a short period in my life (right before my wife left me and my kids). The attacks went away through a period of counseling but they were definitely the worst/scariest times of my life. I feel for you and my son who live with these feelings everyday.
Keep riding. Keep resisting the voices of doubt and fear. Be smart, but tell your anxiety to f*ck-off. You've got a wonderful life to live. It's been waiting for you.
I don't know you, but I am PROUD of you!