Buster, well done for taking the initiative and buggering off to the coast.
I must admit I was a little worried for the both of you when reading your post as I know how this sort of thing can affect you.

I was also in this position. I won't bore you with all the minor details, but had the assessment. Even though I had to be chaperoned there and was extremely nervous and agitated during the interview.
I also received a letter to say I was fit for work.
For one thing, I couldn't go out alone with my monophobia and was practically a hermit for most of the time.

Anyway, during the assessment, which was done by a nurse, not someone who I thought was qualified to assess me in half an hour and led me to believe that everything was going to be fine for me and in fact it was not!
So I wrote a letter and copied it to my GP, who was behind me 100%.
Get you GP to write a letter for you, you may have to pay a small fee, but it is worth it.
The more back up you can get the better.
Even letters from neighbours and family members.
Things can be worked out and even if they have stopped your money, you have to be entitled to some support.
If your partner is out of work at present, she has to receive support anyway.

It's the weekend, so chill out for now and make the most of the sea air.