ESA forms, should I ask for medical evidence?

I received a Capability for Work form which is scrambling my brain. I have been on ESA Support Group since 2014 and now I have to re-apply, I'm really worried about the possibility of not getting into the support group as my health would suffer if I was forced to do 'work related activities', or even worse be expected to apply for jobs. I have chronic fatigue on top of my disability which includes relying on a powered wheelchair to get out, travel is painful and exhausting and I cant drive or use public transport.

I found a folder in my computer with copies of all my documents from last time which included a letter from my GP. But the new form says I shouldnt request letters specifically for the claim - although the guide from this website seems to advise otherwise!

Unfortunately I moved a few months ago and have only seen my new GP once - I had been with my former dr for years and she knows me much better. So ideally I would like to ask both for supporting letters. But I am very confused about whether I should or not! An if not, can I give my former GP's details for them to contact for more info - would she still have access to my records?
Can anyone advise please?

My last assessment for ESA was 2013 and I was placed in the support group , like wise I am filling out my form at the moment , it’s so stressful

BIS wrote:
I am not sure where you have got the impression that the B&W guide suggests you do not need to send in additional evidence.

BIS

The first page of the form says
'Only send us copies of medical or other information if you already have them. Don’t ask or pay for new information or send us original documents.' (my Bold-ing)
So I took that to mean dont ask my GP for a letter. Although I still have a copy of the one my previous GP wrote for my original ESA claim, so I'm planning to use that if I cant ask her for a new letter! Its 5 years old but she mentioned that my condition is permanent and likely to deteriorate, which it has.

Can I ask for clarification about the Descriptors? Do I just need to fulfil one of them to get into the Support Group? If so it would really put my mind at rest alot because I am unable to 'mobilise more than 50 metres' using a walking stick or manual wheelchair, my current physio is trying to get me up to 10 metres with stick on a good day and I cant self-propel a manual chair as my shoulders and hands arent up to it. I use a powered chair to go out and was using it the day I saw my new GP (who referred me for the current round of physiotherapy). Plus I saw an OT before I moved to get a DFG for ramps and a wheelchair lift, so I have several medical professionals who would confirm this.

I should also qualify some of the other descriptors but they are less clear-cut, and also on the 'substantial risk' rules but I've seen so many cases where people have been treated unfairly, I'm really worried that I could be wrongly assessed.

And I really dont want to have to go into full details about some of the questions, my sister is doing the typing for me and there are some things even she isnt entirely aware of, I try not to upset my nearest & dearest more than absolutely necessary.