severe lower back pain for 2 years

My boyfriend, who is almost 25, has been experiencing back pain for two years now. He used to work in construction before college, and one morning, about two years ago, he woke up and could not walk. His lower back was in extreme pain, his left leg was numb, and his left foot hurt when he stood on it. If he put all his weight on his left foot, he would fall over because it would not support him. Since then, he has had 4 MRI's, 2 EMG's and the third one will be this Friday, Feb. 26. He has been on all sorts of medication and nothing helps his pain. He has pain everyday in his lower back, and constantly has numbing and discomfort in his left leg and foot. To even touch a certain part of his foot lightly will be uncomfortable for him. One MRI detected nerve damage, and drugs were administered that did not help. The most recent MRI, which was taken two months ago, showed arthritis all throughout his lower back. He has had two injections in his back to numb his nerves, but one didn't work and the other must have gone in a bad spot because it put him in worse pain than he had been in before the injection. He was just in physical therapy for the third time and has been going for about a month and a half three times a week for an hour and a half each time. The therapist told him to continue his exercises at him since he knows what to do and suggested going in late March to a therapy office that offers pilates. The physical therapy has not helped at all so far. He does not have sciatica or a herniated disc: he can bend down and touch his toes without pain (no sciatica) and xrays and the MRI's show discs in perfect condition. The only thing he can do is stay at home all day and lay around because if he sits up for too long, his back will start hurting so bad he will have to lie down again. He can't work because of his back. He will put himself in extreme pain just to get out and do stuff because it gets frustrating for him since he has to lay in his bed all the time and can't do anything. He had to fail out of his last term of school because halfway through the term his back got so bad he could not attend his classes for the last 5 weeks. He is on his parent's insurance, and since he turns 25 this year, he will no longer have insurance after April 14. We are all trying to figure out what is going on and know there is less than two months until the insurance is up, so we are trying to fix the problem before that time. We are running out of thins to try and doctors to see because nobody is able to help him. We even sent all his x-rays, MRI's, and test results to a neurosurgeon, and the neurosurgeon called, after looking at everything, and said he cannot help. Can you please help? We are desperate to find an answer at this point!