I just had a spinal tap done about 2 weeks ago. I had severe back pain, but mine was the next day. I went to a chiropractor and he said I was having muscle spasms that pulled things out of alignment. I was adjusted and I walked out of there as good as new. Maybe try a chiropractor?
I actually had a leak, too and had to have 2 blood patches. They both failed. I was on bed rest for a week until it finally closed. Those are so painful!!
Has he had an MRI? Of the brain and the spine? There's no reason he should be in that much pain! There's obviously something not right!