Hello @januaryjane
As you know, those of us on Mayo Connect are not medical professionals so we cannot diagnose problems like yours. We can, however, share from our own experiences. I have a form of Parkinson's. I do not have the typical tremors but I do understand the feeling of internal tremors. I have met many people in Parkinson's support groups who have also talked about the internal tremors.
Seeing a rheumatologist is a good idea, and you might also ask for a referral to a movement disorder specialist. This is a group of neurologists who treat specific movement disorders such as Parkinson's and other disorders. Perhaps they could help you with a diagnosis as well.

Will you keep posting and let me know how you are doing?

Hi, @januaryjane - since you mentioned insomnia and hypnagogic hallucinations, you might also check out some of the Mayo Clinic Connect discussions in the Sleep Health group, https://connect.mayoclinic.org/group/sleep-health/. Hypnagogic hallucinations would also be a great topic for discussion in the Sleep Health group, if you'd be interested in starting it.

My daughter suffered with narcolepsy for years before being diagnosed. Several years she would she say she felt all shaky inside. As she got a little older she explained it as vibrating. She has several health problems but when she would mention this to Drs. they would just roll their eyes at her. After being diagnosed with narcolepsy We kind of just chalked it up to a weird thing her body does because of being so completely exhausted. Hope you can figure out why your experiencing it.

Lactose and gluten caused internal chest tremors for me for 15 years. But for two years, no tremors unless I blow my diet.