TMS changing form is nothing new. In fact , it sort of HAS to do something different once we know all of it's common manifestations. Particularly for people who have done this work and 'know the drill'. I have had lots of scary, panicky "wtf did I do?" moments...all of them TMS
If you were stable when this happened then...Something Happened. Period. Something happened in your life that you didn't even pay attention to because it was 'no big deal'. Usually someone very close to us. Family, co-worker, spouse, partner. Work change. New Job. REALLY close.
You either agreed to something you didn't believe, or something with a positive connotation is scaring the shit out of your unconscious. Somebody let you down, or acted poorly. I have never had a 'surprise' out of nowhere when there WASN't a 'something' behind it...and I have been doing this about the same length of time as you.
If you can sit still and review what was going on right before it got your attention, or maybe the day before, and You can isolate the sneaky s-o-b, you can probably arrest this near instantaneously. Your Mind having done the work has faster circuits than the average new person here.
I can also tell you it's NOT that you slept funny or pulled something. That is old Medieval medical model stuff. It's either TMS or it isn't...and if you know yourself and your on this forum, you know damn well in your heart of hearts what it is. Finding it is the challenge, but you know that road so you have an advantage over the average guy who woke up with a crick.
That's the fast forward plan I have always used and it still hasn't failed me. You can remind me of that when I come here with something.
peace