im thinking of never lying again about who i am

While I don't agree with your methods, the idea that other things in life are like PMO in that it's this secret life/side of you makes sense. I would say just say what you really believe with confidence, and don't be shaken. Even if its bad at first, and people will challenge you, it sounds like it could be a good thing. The "winner" of the conversation is the one who keeps his cool, so I would at least suggest that.

 

It's a terrible trap to fall into, pretending to be similar to everyone else in order to fit in. Best advice is to find people you have things in common with, so that you feel that you belong already without pretending. In the meantime, know when to speak up and when to keep quiet, it's not always appropriate to share every thought in your head.

It does sound bad, yes. If you don't care what people think then why say anything at all? It sounds like you are still craving acceptance but without the lying this time.

If you want acceptance then the best way to go about it is to listen and accept other people's opinions too - not to pretend to agree, but to listen and understand their point of view and politely disagree. Some people will be assholes about it, of course, but a lot won't. once you understand that you don't have to agree on everything to be accepted, the idea of blurting out everything in your head might seem a bit less appealing. But you can still be honest.

Does this make sense? Good luck anyway, and sorry if I have misunderstood you.

 

Willingness to be unpopular is a rare thing. Sometimes it's better to be pragmatic and keep your opinions to yourself IMO. For example I downright refuse to talk about politics with my family. There is nothing to be gained from it - the best case scenario is that nobody gets mad.