I experienced this and I am sorry you are going through all this.
In my case, my symptoms were not nearly as bad as you describe. It was more of an annoyance for me. I did a lot of my own research because I originally thought I was a running injury, and doing a kneeling hip flexor stretch is what "lit" that nerve up for me. It took about two months until I realized what it was. I was not pregnant (M here) and I also don't wear a tool belt, sit on a wallet, or wear tight clothing (all ways this might surface).
I did tack it on to some other PT I was doing and none of the nerve flossing or other things you might see online or be presecribed did anything for the Meralgia paresthetica I was experiencing.
Also, I did not find it was induced by activity. I had found some research concerning endurance sports and this syndrome surfacing. That was never an issue, despite multi-hour workouts and racing events.
For me, it just went away at some point, and I can't even remember when to be honest. Maybe 1-1.5 years or so. The good news is that it is not motor related.
You might consider your sleeping posture. Actually looking at the routing of that nerve miight help you consider how it is being further compressed while sleeping.
Sorry I don't have more for you. Good luck!