From my experience with my dad, he had to have a lawyer to help him qualify after being denied. He was over 50 though and his reasons were physical. I'm not really sure what else you can do if lawyers won't take you on. They are eager to make money, so they would take you if they thought you could win. Maybe just keep applying and use your doctor, therapist, psychiatrist, and supervisors as references for your file. Keep doing your best at work, lots of us on here just do our best despite paying into the system since 16, and ask if there is a waiting list you can get on with these lawyers for when you turn 50.