Hi,
I have very similar symptoms to you, I have had tingling and weakness in my legs (clinical muscle weakness as confirmed by my neurologist) for a year, fatigue, pain and also bladder and bowel issues. Among other things.
I have had an MRI of brain and entire spine which was normal.
Neurologist said normal MRI, no lesions, means it's definitely not MS. Even without contrast metal dye, lesions are usually picked up. Contrast only illuminates 'active' lesions/makes them brighter.
I have had every blood test possible and only thing is very low vitamin D. Have you been checked for vit D? Low vit D can make you very weak.
I am taking high does vitamin D, and amitriptyline for the pain. Both are helping me feel better.
I have walking problems too and am seeing a neurophysiologist/specialist physiotherapist. She said sometimes there can be an issue in the functioning of the nerves, like a software problem not a hardware one (like MS). So she said I can do exercises to 'reprogramme the nerves'. This can have similar symptoms to MS etc. We're still waiting to see if that improves my walking. I feel better from it and I would definitely recommend physiotherapy.
I didn't feel satisfied with my diagnosis too tbh, but I was advised against going private by my experienced and lovely Neurologist as he said a private clinic won't pick up anything more on MRI. So I am not sure if anyone else looking at you MRI will pick anything else up (especially as it's pretty clear)? A radiologist and neuro would have looked at your MRI and they are unlikely to have missed something like MS. I am not saying don't go private, but it may not be worth the money (unless you have lots of money).
However, it does sound like you need a second opinion from a better Neurologist so you can at least have a physical exam. Doesn't the NHS patients have the right to second opinion? (I do in Scotland) I would look into this before going private.
I think it's good you are going to a Rheumatologist as you may not have MS, as even Lupus can cause muscle weakness. It's a rubbish wait though.
Goodluck with it all, I understand how rubbish you feel. I hope you can get more help as it doesn't sound like you are getting enough support from the healthcare team x