I had a blood patch back in 2012. I had a lumbar rhyzotomy and epidural on a Friday went home and developed an unbearable headache. The following Friday I was put in hospital, and on the Monday night I had a seizure. The doctors believed the headache was cause by a dura leak and a blood patch arranged for the Tuesday morning. I had the patch done and the headache went away.

I had fractured a number of vertebrae and ribs in the seizure and I can't really remember how I felt post the blood patch because of the pain I was in, so I can't help much other than to say what you are experiencing doesn't sound right. I would get in contact with your doctor so that it can be checked out thoroughly.