Nothing in your original post sounded like ALS...it doesn't cause sensory issues or visual issues.
That said...a clean EMG/NCV rules out LMN involvement, I would assume...but I'd think neuropathy would have shown up. What was the doctors answer on why it didn't?
Personally, I wouldn't give up the quest for answers. The disc problem, not corrected, can lead to per innate disability. Pain is not the criteria to repair a disc. Loss of function, or diminished function are what determines treatment. Lyrica is used commonly in fibromyalgia.
It sounds like you are not really getting any answers. You need them. Oh, and one more thing. ALS is not related to MS. MS can take quite a while to diagnose. It can take a ling time for things to become apparent on an MRI. They found issues in the evoked potential testing. What was the diagnosis what is the treatment for the visual issues in your left eye? (ALS doesn't affect vision)
I hope you find some answers. I'd suggest you see your GP and ask if a referral to a Rheumy is in order. Good luck to you.