Document everything. All your aches and pains, and be sure your doctor knows about everything that you're feeling, from depression to happy days to joint swells...The whole 9 yards as it were.
Hire a lawyer. My mother in law got disability after 3 years of attempting to get it in the first place. She hired a lawyer. They gave her retro for whatever she should have gotten in the first three years and now is getting supplemental income.
I applied for disability back in '02 when I was first diagnosed but I am not eligible. I choose not to work so...I am capable of working 20 hours or less a week, it just depends on if anyone is willing to hire me (i have a very extensive background in retail sales and retail management, not something most people look for in resumes).
Good luck.
Clarebear