I think my "fnd" might just be ME

I've seen 4 neurologists and they've all given me a diagnosis of FND. While i acknowledge it's a recognised condition, I just don't believe that's what I have anymore. I presented to each one with the exact same symptoms: increased fatigue, leg weakness, brain fog, light sensitivity, muscle pain, migraines and joint pain, all of which are exacerbated due to exertion. My symptoms have progressively worsened and I'm now housebound and mostly tied to my bed. Last year I had several episodes which were put down to non epileptic seizures which is why I think they gave the FND DX but they would only occur immediately after I stopped exerting myself, usually after a period of time where my heart rate had consistently been elevated or my temperature was dysregulated. I honestly believe it was just convulsive syncope as I have hyper pots and excess adrenaline can cause me to shake pretty badly, even when I'm unconscious. The more I read into ME, the more I realise it could be what I'm dealing with. My most significant sign that I'm over worked is my legs become increasingly weak to the point where I can't bear weight or walk at all. If I'm consistently in a crash/flare this can look like my legs dragging, wobbling and shaking as I try to engage my muscles as much as possible. After falling so many times, I've given up and just use an office chair to mover around my house. I'm seeing a rheumatologist who thinks I may not fit the criteria for ME but I have to wait until my sleep study is done to rule out anything else that could be causing my symptoms. I don't know whether to keep pushing for diagnosis or just accept the FND one because I'm genuinely so tired.