Meh, your description of yourself as "stuck", struck a bell for me. Along with being "tired".
You're correct, that CoNs know that their survival depends on being quiet, not telegraphing emotion, or giving the N any reason to target oneself for criticism or anything else. Sometimes it happens while practicing that a LOT, like all the time, that one "hides" one's internal world from oneself even - in the fear, that it'll be read on one's face. Ooops.... revealed!
I equated that with a wish to be invisible. LOL. But it was more like my personality, persona, ego, whatever you call it, had been only roughly sketched out - in my inner world. I'd never developed it into a refined finished drawing to present to the outside world. Logically, it follows (at least in my mind) that something that vague and ghostly didn't have a lot of preferences, didn't have much agency or autonomy... wasn't really REAL. It was an idea. And that sure as hell FELT stuck.
Trying to move out of that (and finish the drawing more completely) moved me into an experimental phase; trying things on for size, fit, feel - expression. It wasn't competitive; there wasn't any objective right or wrong (since society is always changing it's standards there) - it was just finding what was comfortable for me, that I felt good about. And I kept going.
Momentum is a strange thing. Once moving, it develops a life of it's own. The only hard part is overcoming the reason for inertia, in the first place. There can be a million different reasons for inertia - fear, resistence, lack of direction, lack of decision, procrastination (as if there is some magically blessed time to begin anything)... and if you're being as honest with yourself as it sounds to me, as you are... you'll figure it out. I got my own struggles with inertia. And knowing when it's my self telling me I NEED to rest or when it's something getting in my way. That I've been putting in my own way, because I internalized something unjust, judgemental, critical or cruel.
Yup; it's still there - but I'm making headway. Usually to do with pick 2-3 little things toward the task and making myself start - because it is something I WANT for myself. For me, it's the want that's the key to kickstarting that momentum. You might find something else that does it for you.
Good luck! (oh - and it helps if you accept any babystep successes at first and don't beat yourself up if you fail to meet a goal the first time)