You'll be approved. I also have Rheumatoid Arthritis, Diabetes, & Depression. I was approved the very first time. I used the law firm of Binder & Binder.
http://www.binderandbinder.com/ They're wonderful! Click on their Frequently Asked Questions (FAQ). That will give you a lot of insight into the process.I had worked all of my life too, as a teacher. I cannot tell you the enormous relief it is not to have to get up early & try to get through another day at work, while in horrible pain. Good luck & God bless!