I do experience this occasionally these days. The only thing I have found that really helps is using CBT to counter the false narrative. It seems to be fairly effective. The fact is for me that I have accomplished a lot. Before I got sick, I had a lot of career success. After I have gotten sick, my accomplishments are different, but no less real. Just being alive now is a huge achievement, given how bad my illness has been and how much SI I deal with pretty much on an every day basis. So, yeah, maybe I'm not knocking it out of the park in my career anymore, but being sober for 11 years and managing my bp1 as I have are much greater achievements than any career award I received in my view. Not completing a suicide after let's just say some serious attempts--that is an achievement.

I can't really speak for PC members from other countries, but here in America, it is totally doable to become a big success if you are motivated and healthy. Opportunity is everywhere. Having a major mental illness/addiction challenge changes that dynamic dramatically. So, in my opinion, it is completely unfair and inappropriate to compare the accomplishments of the healthy me with those of the 'sick' me. These are basically two different people, in large part because the sick me has extremely limited opportunities now. I can't really work. So, saying to myself that I am an impostor these days is actually not accurate. I achieved a ton, if I do say so myself. The fact that I can't do that now doesn't mean those things never happened. It just means I am dealing with a different set of life opportunities today. Just my 2 cents and, of course, everyone's mileage may vary.