Anyone had this happen?

(36 M) I have been experiencing this scary thing some nights and I’ve just put it out of my mind but it’s happened a 3rd time and I can’t brush it off anymore and I was googling my symptoms and it said it sounds like Autonomic Nervous System instability.

When I’m going to sleep and in that in between state of awake and just about to fall asleep all of a sudden I get this woosh feeling in my body like the feeling on a roller coaster when it drops. Stomach in my chest feeling. It starts in my limbs and the feeling rushes to my heart/chest. Like my blood pressure plummets and then shoots up feeling. This feeling will come in waves over and over while that’s happening other weird shit too. It feels like my body stops breathing on its own and I have to very deliberately breath, also will get a flash of warmth in my thigh and it feels like I just peed the bed until I feel down there that it’s dry hah. Also oddly enough got an instant boner that stayed there until I got up and calmed down. Of course the second the first body “woosh” feeling happens my heart rates goes nuts and anxiety kicks in too.. I’m scared af