Hi Jo and welcome,
Your preexisting structural spinal condition, disc fusion and left side nerve damage is your more likely explanation for what you experience on your left side - "loss of feeling in my left leg and left side of crotch, muscle pain and tightness in the back of my thigh and calf, walking issues and need a cane because of the left leg, and I stumble and fall often"
The "squeezing feeling around my middle off and on" could also be related to your spinal issues to but if it's below your rib cage you have to keep in mind that you've had "90% of my stomach removed due to ulcers" and have also been diagnosed with "interstial Cystitis." so there is the possibility that it's related to your preexisting gut or bladder conditions.
You also have other preexisting conditions that would likely account for the cognitive-memory issues you've been experiencing "I also have terrible hypoglycemia" but keep in mind that chronic pain, sleep deprivation and pain medications can also cause these types of symptoms.
The other preexisting medical condition you mention is "horrible headaches" and migraine headaches could actually account for your "left eye pain off and on, blurred and double vision off and on, left sided facial loss of feeling and slight droop" though i would definitely recommend you get the health of your eyes assessed if you haven't already, at least by an optometrist, preferably an ophthalmologist because with your medical history there is a possibility visual issues are is a co-morbid situation happening.
MS is a disease of the central nervous system so just about every associated MS symptom you've read about can also be caused by 100's of different types of medical conditions, usually more common causes too.....its rare these days but MS can still be diagnosed without MRI evidence, apart of the collective evidence requirements though is for there to be no other more likely medical explanation for the symptoms and neurologically suggestive signs.
So with that thought in mind, what you are experiencing is diagnostically 'more likely' to be associated to what you already know, than for you to be dealing with an additional unrelated neurological medical condition like MS....
Nerve pain can be very difficult to get under control, many of our community members have experienced a lot of help and support with their pain situations after specifically going to a 'pain clinic' so that's something you might consider doing.
I hope that helps......JJ