Sounds like your situation/box is the opposite of what mine was. Before I knew transition was possible, trying to live as female, my only-partially-me "character" hinged on trying to seem friendly and non-threatening. Because people often responded poorly to me. I struggled to be more expressive and emotive than I really am. Probably everyone alters their personality/expression to some extent, it's a necessary part of socializing in many situations, but it's unhealthy when it's a most-or-all-the-time acting gig. That's where mine went and sounds like yours has too.
Perhaps start by entering a new social situation - even an internet forum - where people don't know you and don't have expectations of how you act. There, drop the "character". It may ironically feel awkward and forced at first, but at least there won't be any chance of "Gee, GnomeKid, you are acting different today" comments. Can't say how to deal with people who already have expectations of how you act without "making waves". I expected things to be more awkward when I dropped my "character" and with some people that's the case, but that is so small compared to how hard the character was to maintain, I'm not bothered.