Welcome to Wrong Planet, Yury!
Yes, as Claradoon said, it's is a very common experience among people here. From what you say, it sounds like you are probably quite good at "masking" - using vast amounts of energy and brain-power to work out what you "should" be doing when you're around people, and then adapting your behaviour to fit as best you can. Most other folks can't see the amount of effort this takes; it's more often a sub-conscious thing that seems to happen without any willpower for them. Catch-22: Every effort to "better yourself" becomes evidence that you're "not really autistic" to other people, because they're only judging the outcome, not the difficulty in achieving it. But if the "brain-drain" becomes too much and autistic traits "leak out", you get accused of not trying hard enough. Exactly as you said, you can end up feeling that you can never be your true self around people, and that is not good for one's mental health.
But that isn't something you need to worry about here - it's a place where we can be completely open about these things, and maybe even learn a few strategies to help us cope with them better!
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When you are fighting an invisible monster, first throw a bucket of paint over it.