Nervous about medical tomorrow

Ive got my medical tomorrow for my PIP CLAIM and I feel physically sick from the thought of it. I have paranoid schizophrenia which is usually well controlled by medication but since I got home from work tonight I started a near fight with my husband from the stress of it all.
I will be driving myself to the centre tomorrow as I am petrified of public transport. A part of me feels like "giving up" as I feel they have probably made their decision anyway before ive even arrived..And I don't feel too optimistic about my chances of getting PIP.....And it's giving me a real downer...( I just feel so discouraged right now - compounded by everything else happening in my life, my mum in laws cancer is getting worse....…my step dad could be diagnosed with cancer for the second time....My mum died last year and I'm still grieving. Plus I had a mini stroke myself last year)..Help!!