UC WCA decision

Hi there,
I've just received my decision on my WCA. It says I do not have limited capability to work. The last 5 months my GP has given me a fit note saying I need to only do 10 hours work due to being badly anemic.
I have a small dog walking/pet sitting business which I started 15 years ago when I was on ESA. I had a limited capability for work as I have lupus but wanted to work & knew exercise helped my joints plus my mental health so started dog walking. It was the best thing I've done as I managed to get up to over 16 hours per week quickly, come off ESA & onto WTC (16 he minimum week required as I get PIP too). I was on low rate mobility & low rate daily living PIP but on renewal (& after the appeal) they only gave me low rate daily living as they said I could walk fine being a dog walker/pet sitter. I did explain that on bad days I can hardly move & so the dogs that I'm pet sitting just have the run of the house/garden & I fit in dog walking round my bad days. I also said I rent an enclosed field for days I can't walk but because I said this they said I had mobility issues. I said that my 16 hours could be just 2 x 8 hour days pet sitting with no walking at all. Still no so I gave up.
Anyway after, 13 years on WTC (& PIP low rate daily living for about 7 years) I had to go onto UC. They said 16 hours a week was fine so all was good until I became really ill with anemia & had to have 2 iron transfusions after other tablets/liquid didn't work. I was only able to do a couple hours a day cos I was so ill but they said as long as I got my hours up to 16 again that was fine. Second infusion I had a severe allergic reaction & stopped breathing but by this point my iron levels were a bit better so I just carried on trying my best. I was only able to do about 14/15 hours but then the iron levels dropped again. My GP did fit notes for limited hours (10/week) & I thought it wouldn't be for long so didn't worry about it. My coach said I could just go back to 16 hours when Id got it sorted as I thought it would get sorted in a few months. 5 months later I've had a letter about a WCA which I thought would be ok &, I'd explain I couldn't walk far without being exhausted, not being able to breath & getting chest pains, that my GP was in the process of trying different things & refering me to someone to investigate further if they didn't work. Stupidly I thought that because my GP could see I couldn't function & therefore wrote a note & because I couldn't walk even half the length of a football pitch without nearly collapsing that they'd say I was ok doing limited hours until I'd been to see a specialist. The last thing I wanted was to loose my clients so even cutting my hours down was difficult but they all understood.
This letter says I'm fine to work & I presume means if I can't do my current job then I have to pack my business in & do something else! I just wanted time to get well so I could pick up my hours/more dogs. Getting a job working for an employer has been a nightmare previous because of the lupus & the flexiblity I need to be able to work around the lupus. Last time 18 years ago they'd pushed me into work (for employers) but each time I'd either have to take loads of time off sick or I just couldn't cope so had a "melt down" (I get anxiety/depression too). Plus also I struggled mentally as I have ADHD but wasn't diagnosed until this year & this affected how I coped with lots of work.
Anyway, I'm in such a state about it all as it sounds like they think I should work full time, rather than go back to the 16 hours minimum I used to be on when first came over to UC/when on WTC. My iron levels are up a bit so I've a little more energy so taking a new dog on but my hours will only be 13 per week until I can get a bit better. We're (GP) now not sure if it's just the iron levels or if it's my lupus too.
So I just don't know what to do. I'm not wanting to stop work, I just wanted time to get well so I could build my business back up.
If I do a mandatory reconsideration what do they sety hours at? Who do I discuss it with & how do I do the mandatory reconsideration? I'm in such a state mentally since getting the decision (because I was so sure they'd put me on low hours & review it from time to time to help me get better/my business back up to scratch) that I just can't think properly, understand things I'm reading & my depression/anxiety have sky rocketed which is affecting my work. My job coach suggested a couple of months ago that I go as my husband's carer on UC (rather than claim carers allowance) but then how can I be someone's carer when I'm claiming PIP for myself. It just seems dishonest! She said that means I would have no limit on my hours & could work as little/as much as I wanted (as long it was the carers element of UC & not carers allowance). Surely if I'm saying I care for my husband (he's on high rate both mobility & daily living PIP) then I can't have low rate daily living PIP? It just seems such a muddle!