I haven't had PTSD that I know of but I have had feelings like you describe. I had been in therapy about 4 years and if anything I was getting worst. I then connected with a therapy group and decided to give it a try. The first night of the meeting I was surrounded by other people in transition and I felt like I didn't belong. I felt I didn't have the right to be among people who had accomplished far more than I had. I also felt that I was and impostor. It took me a while to work through this in my head. When I returned for the next meeting, I still hadn't got that feeling out of my head but I was going to try a few more meetings and if they objected to my presence, I would leave without a complaint.
What happened was I started meeting people, talking to them and sharing. I found that we weren't that different after all and soon I was the one helping the newer members adjust to the group.
You will need to make the first move and open a conversation with others. The guys on this site are really helpful and great. You will be surprised as you transition how the powerful feelings you currently have will diminish. I went from suicidal to somebody who is happy all the time. Just be open to the help we offer and the changes that will happen.
