After one year ESA, new medical form arrived now

I have been on ESA for nearly one year now, I have passed the medical assessment in April and May period ,(I have appealed and win ), But now the new medical assessment form come to me again? Do they assess you like the first time again once more ? Then if not success, you could move to JSA ? How to fill the form correctly and they also ask to submit medical document to job centre?I don't know what kind of medical document they need? If I can't pass, then JSA also fine for me, but what is the main difference between JSA and ESA ? I'm in ESA work group which they often ask me to go to there to seek for job as well. Almost every two weeks ,I need to go to there and sit there to search jobs ,which is no difference with JSA already, isn't it ? Thanks for your kind help!

But actually they asked me to go to there to seek jobs ,next appointment is 19th of Dec, then January , even I told them I would like to move to self employed job, I have wrote business plan and let them see my business plan, they have asked a business adviser to communicate me often, but they still ask me to go to there ( a company partner with job centre to help people find job) . I don;t know where to complain?Even last Thursday ,it was very windy day in scotland ,the school closed at 12 clock, they still asked me to come there which is hard for me to go, but ...where to complain? thanks.