I totally understand. I work with the public,...healthcare. You can see people at their literal worst, both physically and mentally,...patients and co-workers. There is the "attitude" aspect,...how you feel any given day,...sometimes you are head-up, good posture, bright-eyed, got a bit of pep in your step,...and it seems easy to be friendly and receptive to others. However, there are those other days,...quite the opposite,...and it can be a bit of a struggle to consciously be "in character" and try to be social.
As an autistic, I know that my dopamine levels can be quite low,...and it doesn't have to be on the order of clinical depression,...but I'm certainly no "life of the party" either. Varying levels of depression or "flat affect" is one of many characteristics associated with autism. So, absolutely, this affects how we interact socially. It IS more difficult to present yourself as friendly and socially interactive when you clearly are not "feeling it". It's acting,...plain and simple.
This is where many of us find this internal, psychological conflict within ourselves where we are highly aware that we are "in character" or "masking" for the sake of being "socially appropriate",...whatever that is within the context and perspective of our social environment. Whether you are at school, out with friends, at work, a job interview, talking on the phone with a customer,...whatever,...you will be, at some level,...adjusting your behavior and tone of voice to the situation. Some are much better at it than others, no doubt, but we all have to do it,...even neurotypicals. As such, I believe that all of us, at some level, have our moments when we feel "fake",...and it does bother us psychologically.