Hey MNC ...
I have a very similar story. I took MDMA in a therapeutic setting just over 1 year ago. Since that time I have battled countless neurological problems, including neuropathy of my feet legs and hands, tinnitus, brain fog, depersonalization?, hypnic jerks and hallucinations...
I don't have any visual disturbances so i'm not sure whether I fit the HPPD criteria. But it toggles back and forth for no reason. I often have 4-5 days of relief, followed by 1-2 weeks of symptom flare up. Exhausting.