If you made a recovery on abx then that tells me your problem is bacterial in nature.
The injury could have taxed your immune system in some way. That is what happened to me. Ok until after child birth and a few surgeries that sent me into a tailspin.
The spinal shows lyme only about 5% of the time. The lyme blood test takes about 2 weeks so that sounds right for the spinal results.
I don't know about transverse myelitis. What test give results for this dx?