Hope you are doing ok

This is my first post here. I will try to make a long story short ;)
My journey began 3 years ago (I was 20 yo) with some mild neurological symptoms (muscle weakness, mostly in left leg and slightly impaired sensation on the left side of my body). I was admitted to the hospital where I had brain and cervical spine MRI, spinal tap, EEG - all clear. Neurological exam was fine. Also tested negative several times for Lyme (both blood and spinal fluid). I was told I am ok and should keep living normally and so I did. I was even able to do sports. The symptoms never went away but I managed to live with them quite well. Everything changed this year. The muscle weakness got a little bit worse (still only on my left side), the muscles in my left leg are a little bit stiff, constant exhaustion, complete heat intolerance, horrbile back pain (also had a lumbar MRI - clear), tingling, burning sensation in my skin, I tend to bump into walls and furniture, horrible brain fog, fasciculations, problems with urination. Two weeks ago I went to ER with what I thought was sciatica. Got some pain meds and was told to come back if symptoms persist. Neruo exam was ok. But I went back two days later because muscle spasticity in my left leg got worse. Also in neuro exam I had positive Babinski sign on left side, and Jacobson reflex in left arm. Was admitted to the hospital for some tests as "MS patient". The MRI of brain and cervical spine came back clear. I am still waiting for the results of the spinal tap, but my doctor is convinced I will test positive for oligoclonal bands. I will also have later VEP (not sure when). Anyway, I was discharged with Dx "Observation towards multiple sclerosis" but was told to register at MS clinic... I should have my results within week or so and will let you know as soon as I get those. I will be also going on a visit with some good MS doctor shortly.
B12 deficiency was also ruled out.
I was wondering if it is possible for changes in MRI to appear after years of active disease? I just really wish to already have a diagnosis to get the right treatment (although where I live MS patinets have it very hard to get a proper treatment).
All the best for you,
Aleksandra