I have never taken psych meds long term but I do feel that many years of experience and self awareness has modified how I view myself, react to situations and where my priorities are. I do feel the discrepancy when I deal with personality tests as I think (I posted about this above) most target stereotypes and simplistic concepts/interpretations. I do need to consciously decide whether I want to complete tests/surveys like these using my default reactions/answers or the views I have developed via life experience and self work. I don't feel that there are huge differences and contradictions but lots of subtle things and I no longer find these kinds of assessments very helpful, I don't find anything new in them. But it can still be fun.

As for the "altered self" due to medications, years of therapy, life experience etc - my view is that if the result and change is constructive, I much prefer to consider my current way of being my true self, here and now. Many of my older, earlier ways of acting and thinking just no longer work for me and/or if I acted them out, it would feel like regression. And since that's not what I want/find useful, I prefer to take who and what I am here and now as the most significant and "real". This includes if I am dealing with problems here and now that were not issues earlier, because ignoring them would not generate progress or give me a sense of satisfaction and being aligned with my values. I think some elements of our personal values and sense of self are established early in life, but not all. I like to see it plastic and dynamic, not steady and something completed in the past.

Psych meds can indeed change how we feel and react to situations - that's the whole point! If you don't feel happy with how the meds work, maybe change the regimen or try stopping if that is safe for you?