Going through hell with managed migration

Hi, we're a mixed age couple, both disabled and are being migrated from WTC to UC by managed migration late December. We've had a nightmare 8 weeks trying to sort everything out and although we appreciated the help from Citizens Advice they did unfortunately make things much more complicated and caused long delays. Every person who dealt with us gave different advice which just confused everything.
We are very ill, we are both self employed and this is our busiest time of year for work. We can't cope and the stress & anxiety has made us ill. We have the UC accounts set-up and the UC team are now causing problems. Today they made an appointment for my partner to attend the jobcentre tomorrow morning to prove his ID even though they have been told he is immuno-suppressed and it's not safe for him to be in crowded places as he is at risk from Covid/Flu etc.
He is too ill to attend and has already provided proof of ID and was supposed to get a phone call about it. Is there anything we can do about this as they are putting so much stress on us both it's very detrimental to our health as our conditions are impacted by stress.
My partner will be taking his pension in early January and will be lessening his working hours as he will be just about retiring and he is in the process of claiming Attendance Allowance.
I have a phone appointment early Jan to prove my self-employed status even though they have most of the info already. We are at a loss at what the UC team are up to as they seem to be being awkward for the sake of it - it's a stressful enough process as it is without all this messing about on top. They have all the relevant information from our WTC awards over the years so why is there all this extra palaver when they already know everything.
They are making the changes, not us so why put so much stress on us. Surely it's disability discrimination.