Hi all - I'm new here, but I've been reading for a while.

Currently, I've got something that I think sounds a lot like transverse myelitis, and I was hoping some of you can help me figure it out.

A week ago, I woke up and my left arm was numb, sort of like when I sleep on it wrong and wake up to find it asleep. It progressed to pain, weakness, numbness and tingling, and it felt extremely heavy. After a few minutes being up, my left leg did the same thing. I made it through a half-day of work (I'm a high school teacher), and then went to see my GP. She did a neuro exam and found reduced reflexes on my left side, reduced sensation to temperature and pinprick. I couldn't walk on my toes or heels and I was in awful pain.

After a neuro consult, she sent me to the ER so I could have an emergency MRI. The brain MRI was clean of stroke and MS legions. I also had blood drawn, which showed elevated SED rate, but nothing else abnormal. Eventually, they released me and said that it was "probably a migraine." But after it didn't go away, the neurologist said that's not even a possibility.

Over the course of the week, I've learned how to walk a little better, but the symptoms remain the same. I do have more shooting pains than that first day, and tons of muscle spasms, including cramps and spasms in my left calf for the last two days - nearly constantly. I also have intercostal spasms and muscle spasms in the chest wall, which feels like a knife in my heart...all that is on the left side only.

I saw a neurologist who did another exam and found the same results as the GP. He ordered a thoracic and cervical MRI, which haven't happened yet. But he has no idea why this happened or what it could be.

Medical history:
--diagnosed with rheumatoid arthritis in 2004, treated with methotrexate
--after several UTIs, methotrexate stopped and I had sudden onset chronic mid-thoracic pain (on-going since Nov '05) which is treated (and semi-controlled) with flexeril and morphine.
--clean MRIs, bone scans, blood work, CTs, X-Rays, and a mostly normal EMG
--after years of testing positive for rheumatoid factor, I became RF-negative, and the diagnosis was changed to sero-negative RA. I've never accepted that as the definitive diagnosis because other than joint pain and positive ANA, I had no signs of the disease.
--chronic migraines have been a problem at two points: 2005-2006, and the past 9 months. I had 22 migraines in Jan '13. Since going on Verapamil in Feb '13, I have only had 3 in two months.
--I've probably had 15 UTIs in the past few years (at least 5/year going back to '07), and a few have progressed to a kidney infection. Latest one was a few weeks ago, and I was in the middle of antibiotic treatment when the TM/neuropathy problems started
--in '05, before the back pain started, I went camping and came back with a rash that looked a bit like a bullseye. I've always wondered if that was Lyme, but I've tested negative on the standard blood test for Lyme and no doctor would order the more accurate one.
--my symptoms also struck me as being more like Lupus (tons of skin rashes, joint point, sensitivity to sun, fatigue, slight fever for extended periods of time, Raynaud's, chest pain, kidney infections, headaches, fogginess, sleeplessness, some other mental processing issues during "flare" periods) than SN Rheumatoid.
--I've asked my neuro (via email) for corticosteroids in the hopes that they'll help.

So here are my questions:
1. Does this sound like an autoimmune case of TM?
2. Is it possible that the original back pain episode could have been TM?

Or, is there another solution that I haven't thought of? There's way too much here I know, but I was trying to be complete. Thanks for any help you can offer.