Hi momtothree. I am sorry you have terrible back pain. From what I understand, steroids are bad for Lyme patients because they suppess the immune system which can make Lyme symptoms worse.
Dr. Burrascano briefly discusses steroids on page 4 of his treatment guidelines at http://www.ilads.org/lyme_disease/B_guidelines_12_17_08.pdf:
"...More severe illness also results from other causes of weakened defenses, such as from severe stress, immunosuppressant medications, and severe intercurrent illnesses. This is why steroids and other immunosuppressive medications are absolutely contraindicated in Lyme. This also includes intraarticular steroids. " (These words are bolded in his guidelines.)
You may want to do further research and check out all possible options.