Welcome to the forum, Epi!
I am also on SSI and just went through my first re-evaluation after they approved me in 2005. I survived it, but after many tears. My advice to you now that you are iron-clad approved is, start making a list of every doctor you visit and what for, if that visit has anything to do with your disability. Write down the name, address, phone number, date you saw her/ him, all info. When you get your re-eval letter in 3-5 years, you will be able to fill that form out in no time, even if you happen to be going through a mental illness fallout at that time.

I already had 100% service-connected disability (physical disabilities) from the VA when I got approved by SocSec, and I ain't ever going to miraculously become healed/ cured/ well. But still, you know how the govt works, and they had to go through the whole damn thing all over again as if I was not disabled at all.