I have a lump on my lower back (pretty much directly parallel to my spine)

I have been in and out of hospitals since 2006.

I had been in a severe horse incident.

For the last 3 years I have been watching over myself, and noticed a lump on my back. Being in and out of hospitals no one has been able to give me a reason or diagnosis as to why my back is swollen and why my left meg is weak and gives out randomly.

All my blood work is coming back normal. My xrays, ultrasounds and mri's are clear.

Can someone please help me or guide me in the right direction.