I can definitely relate. I come from a very dysfunctional family as well. I always feel like an imposter. Every time I try to accomplish something or try to have relations with "healthy" or "wealthier" people, it feels like I don't have the right.

I always feel like I am from the wrong side of the tracks. This was a big issue for me in therapy, but all my therapist could offer me was that I could cross over the tracks at any time.

Any thing I have accomplished, any talents I have, seem counterfeit, any relationships I have with people (who come from the right side of the tracks) I fear I will be found out as a fraud and thrown back to the other side.

Sorry, getting long. There are a lot of good ideas here. Just wanted to share that I really get it. I hope you can find a way to overcome these thoughts.

Fake it till you make it, I'm not sure, how will I know when I've made it? With this type of thinking one will always feel a faker. So I guess I would think until the distorted thinking is corrected, fake it till you make it might not get you past fake. I dunno if that made sense.