Feeling confused

I have all the symptoms of Parkinson’s, but after a normal MRI and datscan my neurologist thinks I have Functional neurological disorder, however my uncle who does have Parkinson’s believes I do as well.

So I have been for a week now trying mucana pruriens (L-dopa) natural source of levodopa that my uncle suggested, and it has worked wonders and has really helped me out with my tremors, movement, even my speech improves while it’s in my system.

once it’s gone it’s like the come down from a sugar Rush and everything comes back to normal and hits me hard. I’m just so confused as it shouldn’t be working if I do have FND and not of.
Any one else experience this and had there diagnosis done by a form of levodopa challenge test