The one thing lacking from your post is the results of your testing and the opinions of your doctors.
I went back and read your 'onset' timing. Did you know that there are a LOT of people with fibromyalgia that get the syndrome after an infection of some sort? (Or an injury)
Fibro can cause a lot of the sensory/pain/feeling weak issues you describe.
One of your older posts mentioned a pinched nerve I think--how was that determined? MRI? EMG? (I'm assuming your EMGs were clear--and if you've read here much you know clear EMG = no ALS)
Your reflexes were fine--so no apparent UMN issues on clinical exam. EMG clear so no LMN issues detected.
All that doesn't mean that something isn't explaining your prolonged issues--it just makes the likelihood of it being ALS about non-existent.
Are your lab values that show muscle wasting elevated? Has a doctor seen actual muscle wasting or are you seeing it?
If a DOCTOR sees it--then it's their job to track it down. If they aren't seeing it--perhaps you've become too hyper-aware and are looking for problems that might not be there? Or are you doing less and loosing muscle mass from less activity?
I hope you get sorted out--but after this long, there would be progression to the point of some major level of loss in at least ONE area by now, I'd think--an arm or a leg, etc.