Sleep clinic in Tokyo?

Does anyone have experience with sleep clinics in Tokyo? I found a few from Google but if I’d like to hear if anyone here has anecdotal experience.

I don’t have problems sleeping but I always experience really wacky and weird dreams. That on itself is not a problem but I go in and out of being lucid and have frequent dream in a dream situation. That again is just a dream so no alarm but everytime I wake up I get jolted off the dream with high heart rate and deep breaths.

Maybe, just maybe I am choking myself while sleeping that’s why I have wacky dreams and loud snore. So loud I wake myself up sometimes. Thankfully I’m still by myself so no risk of partner trying to snuff me off with a pillow. But I definitely want to get it checked up. My Japanese is fluent