SSD denied benefits

I have been out of work due to lumber radiculopathy, chronic lower back pain. I was denied by SSD and was recommended to get advice from an attorney if I would like to appeal. If I could work I would I've tried getting cleared for work and Dr can't provide me a note that I can go back. I honestly have good days but the pain always comes back and its not consistent, I got the injection and it helped for a month and back to painful days. they say that there dr said I am able to work. what do you think I should do?