Failing to manage work and childcare even when I am trying my best.

Surely if you keep being ill due to work management sickness protocols, ie children with diarrhea don't immediately get sent home then surely that can't count against your sickness record?
Perhaps work need to reconsider health and safety (cleaning up after ill children etc) and when they send children home/don't allow them to come in.
Also look at whatever you can do to boost your own immunity. Being constantly ill for a chunk of time can really knock you for 6!

Is that going to be helpful to parents to have a childninder who is always coming down with something though? If the OP did that surely she would be screwing over her clients leaving them without childcare each time she's off sick

If you’re at risk of losing your job your husband needs to step up and take some days off. End of. It makes zero sense for you to continue to do it and end up losing your job.

What about switching to nannying or childminding op? Fewer children to care for so fewer germs and more flexible in terms of days/hours.

What happens with pick ups and drop offs - it sounds like DH usually manages these but you will take emergency leave if he’s got something important at work, or have I misunderstood?

If this is happening frequently it will compound the issue. Can you organise breakfast and after school clubs?

Can you change to part time? It would keep your employment ticking over but buy you time to keep healthy.
Use unpaid parental leave for holidays and keep annual leave for kids sickness. Also use unpaid emergency leave if its critical.

I swear I have PTSD after those early years as a working (PT) lone parent with limited, then no support.

Firstly, make sure your immune system is getting some help with vitamins etc.

second, can you change jobs - some agencies supply staff to nurseries across an area when they need staff are to meet their ratios. Like “bank” shift worker. Then you could simply refuse shifts when you’re ill or you need to look after kids. Could something like that work?

If you work in childcare have you thought about setting up your own business as a childminder even just doing local school pick ups/ drop off can be quite lucrative

Are you genuinely a sick person? Are you school/nursery sending kids home unnecessarily? This seems an unusual amount of sickness and ill health. My last day off sick was 6 years ago with covid, and before that who knows, maybe 3 days in 20 years! I also have 3 children and work from home if they are sick. But again, handful of times over 11 years and split with husband, so maybe a couple of days when I have been wfh with a sick child.

Your employer needs to stop accepting sick kids into the nursery for a start, it sounds like a plague infested hell hole. Do they have good hygiene practices? Good ventilation, cleaning, etc. Do you have all your vaccinations eg flu?
I would be looking for another job that is less germy. And yes have a check up to see if you have any underlying conditions.
If you're not turning up to work that will leave them below ratio potentially so I can see why they are being strict. It is hard if you've no back up but the usual back up for childcare, grandparents, wouldn't want to be exposed to stomach bugs either so it's up to the parents (both of them) usually if kids are sick.

It doesn't seem as if the DH is always ill

OP, I'm also on Stage 1 sickness/absence (I'm a teacher), as is another colleague with similar age kids in my department. It's shit because I definitely feel that I do as much as I possibly can to avoid being off, but sometimes you get sick and kids get sick.

I work in health OP and theres nothing wrong with you. Its a natural immune response. I'm actually quite angry on your behalf...they're expecting you to work constantly around little ones with repeat diarrheah, fevers, stomach bugs, and so on, then criticise you for catching the bugs you are constantly exposed to?

Have you thought about private care? I had a friend that did that as private childcare out of her home. She always had a small group of kids and seemed to really enjoy it.

Op, sometimes life takes over and you just need to do your best. Start looking for another job, not because it will be better but because you can start with a new slate not having the stress of a disciplinary over sick absences as you have had so many already. It will also be easier to find a job if you have one than if you have been dismissed.

with regards to catching so many bugs… after years of working in a hospital I can say that the way to avoid illnesses is relatively simple, as with Covid… wash your hands all the time, don’t put them near your face and do not ever lick your fingers. If your children are still sucking their thumbs or licking their fingers after touching food… they will be ill all the time.

First off, it sounds like you're in the very worst part of this where your children's immune systems are quite undeveloped, and it will get better. In the first year she was in childcare my DD was endlessly off sick and I thought it would never end, but it did.

But I agree OP that your DH needs to step up here. It sounds like he has the important "big job" syndrome. It's simply not sustainable in a two income family for one parent to bear all the cost of childcare-related absence. Much of the point of being in a partnership (as opposed to a single parent family) is to share the load.

Is your DH aware how close you are to losing your job?

I’d personally be concerned if you’re all getting so sick you can’t go into work/nursery/school this much… I understand young children pick up viruses a lot but it’s not often they’re so sick they can’t go to nursery surely. The only reason I kept mine off at that age was stomach bugs or particularly high temps, otherwise they went in with Calpol and nursery were happy to accommodate because I was paying a lot and we both worked.

Are you with a union? If their policies are in part contributing to your illness then surely they’re in a tricky position talking about you losing your job?

I seriously doubt your work will follow through on their threat. Good childcare staff are like gold dust. I’d start looking for a new job where they don’t make threats to you for circumstances resulting from their own sickness policy

Can you look for a job in a different nursery that has a stricter policy on child sickness? Many places will send kids home or not accept them in for one instance of D&V or a high temp.

I think you should ask your work to do a risk assessment regarding staff catching illness from children in your care. It may make them think twice about sacking you if they get a hint of an employment tribunal looming. Put it all in writing and keep records. You have nothing to lose by doing this and it might actually get better