In my experience, SSDI determinations are very screwy. Many people who are obviously very disabled have difficulties being approved. Others who look just fine (in the slim minority of applicants) get approved without a problem. Your attorney is wrong though, and a bit dramatic. There are lots of causes for disability which the government does often accept. Try not to let his/her incorrect words worry you.
I can't think of any companies that help through the process, but I do know that they are out there. I was in the slim minority of disabled that was approved on my first try. I also know that Social Security really appreciates getting
absolutely complete information (from doctors and such) in a very timely manner.
A local group, SEMCIL, was a great help to me through many things. I know that they're a national organization, but I can't recall their national name. Sorry

! I just can't recall much else to help you. Best wishes and hugs to you.
Shez