I had a review about a year ago. It went fine. Apparently about 95% of appeals are approved and if you aren't they keep paying you through an appeal, so the first thing is don't panic.

I had the same fears you did. But I just had to fill out a form detailing my ability/inability to do a large number of thigs (just focus on how hard it is for you to manage tasks, what extra help/time/meds/etc you need). Then my therapist got a form that was pretty similar. They were very similar to the forms you do when applying.

Both forms went back in and a few weeks later I was told I was good until a next review in 3 years.

Hang in there. It will be ok.