Thank you very much for getting back to me. I will check into it.
It is likely to be compression of the sciatic nerve.
The buttock pain is fairly definitive. A Lumbar MRI will be conclusive.
After this diagnois is confirmed you need to go to a physical rehab specialist who will, for starters, teach you some exercises that will relieve the pressure. A electrical tens device will sometimes relieve the pain, as well as a transdermal 5% Lidocaine patch, to be used for no more than 12 hours at a time.
Eventually you may require a procedure known as a laminectomy.
Keep well hydrated, avoid riding in a bouncy vehicle, resolve to always lift properly, and hopefully it will get better.