I agree with you that being 22 puts a different spin on things. I was 29 when I was diagnosed with cancer. (I just turned 30) We are WAY to young to think about death.
I understand your worry. Get a second opinion. You are correct, sometimes doctors miss things.
This group has been so supportive to me. This is the only place I can go where people understand what I have been through. So many people here have been through so much. I would give almost anything to erase the past few months, to have never had to deal with any of this. I think that everyone on this board feels the same way. Get the second opinion, and then put all of this behind you.