ESA telephone assessment-Parkinsons

Hi everyone
I have early onset Parkinson’s disease and was diagnosed about eight years ago. I’m currently not working having handed my notice in 11 months ago because I was slowing down at work. I am now trying to claim ESA. Due to Parkinson’s being progressive with no cure I thought I might go into the severe conditions category as I do seem to tick the criteria but would this be considered after the tel assessment?
So I sent in a detailed ESA 50 form with a lot of supporting evidence (from consultants my nurse and discharge letters from the physiotherapist and neuro psychologist that I saw in the last 5-12 months) and was hoping that I might have a paper based assessment. I contacted Serco again today who confirmed I am going to have a telephone assessment which they booked in for me in a week or so.
Just wondering, what kind of questions might be asked - will they just go through my ESA 50 form and confirm my answers? My symptoms vary a lot depending on if my medication is working, if I’m having an on or off period. I also suffer with anxiety and can get a bit flustered on the phone and I’m worried I’m gonna mess up on the call and not be able to explain my condition and the way it can affect me. I was hoping to have some info from you in the following if possible please…..
Any advice on how best to prepare and tips for the telephone interview…
Is there a copy of questions that I can expect they’ll throw at me so I can prepare..
Anyone else with Parkinson’s been through this successfully- hints and tips..
How long after the assessment can I expect an answer?
Thanks 🙏