There are many health conditions that can cause internal vibrations, I believe. You just need to figure out which underlying condition is causing it for you.

Nazzi, you wrote, "I have a PD and I feel it originates from that." By "PD", do you mean that you have Parkinson's Disease?

If you look at the comments on the "internal tremors" and "sleep vibrations" groups on Facebook, you will see that a whole host of medical conditions are associated with internal vibrations, whether yours happen 24/7 or only during sleep or waking. I hope you find some answers soon!