UC Phone Assessment Wednesday - Anxiety out of control - Advice welcomed.

Hi folks, I apologise if I'm posting this incorrectly. But I need some advice.

So I have a UC health assessment via phone on Wednesday and my anxiety is already out of control and I can't stop worrying. I've never had a phone assessment before, with my previous one being face to face which went terribly. In some respects I'm glad it's via a phone call because I asked for that due to physical limitations so I wouldn't have been able to make it to an assessment centre. But I just don't know what to expect. My mind is running wild, I've been sick twice and I can't sleep.

So I'm looking for some advice from those who might have been through one before? I previously had an assessment for PIP which was an awful experience with an assessor who barely asked me any questions and couldn't have cared less, which left me feeling worthless and depressed for many months afterwards. I'm worried I'm going to go through a similar experience here and I think that's what causing a lot of my anxiety and worry. I really don't want to go through that all over again. I just don't know what to do. I'm currently looking through the guides providing on the site but some advice on how to cope with anxiety would be very much appreciated because right now I'm a mess. It would be very much appreciated.

Sorry if I'm rambling here or if this is the wrong place to ask such a question.
Thanks.