Hi DuckyD and welcome to the forum,
Please bear in mind when reading your replies that no-one know you or shares your exact circumstances or emotions. We try to help, not upset.
My immediate thoughts were, you have heard of bright, healthy and energetic people who take a walk along the sands at low tide and suddenly find themselves up to their knees in quicksand and the sea is coming in?
If you are looking for suggestions as how to cope with drowning I think many of our members would prefer to throw you a rope and help haul you out of there.
First of all try to accept the fact that no-one has to care for an adult, no matter what the relationship. Not legally, not morally, not at all.
Secondly, although I appreciate your experience and willingness (initially at least) to look after all these people, just one of whom would probably send many a carer into meltdown, you are not Superwoman. You can’t possibly look after them all. However much you want to or think you ought to.
Thirdly. There’s no doubt that as far as the parents and granny are concerned it is only going to get worse. Much worse and maybe for years and years. As for your fiancé, well, in my experience people don’t change but sometimes they try if only to please someone they love? Is this what you signed up for?
If you want to keep involving yourself with all these people, then you must become their care manager not the carer. Concentrate on organising the help they need, not trying to provide it yourself. Lots of advice on here on how to go about that.
Never forget that you are important too.
Hi Duckydinosaur, (interesting pseudonym, is there a story behind it?)
Welcome to the forum.
You are most definitely a carer.
I have no experience of caring for someone with MH issues, but a saying on the forum is either you enable them to stay as they are or you set up situations to help them help themselves. I therefore suggest you stop making your fiancée breakfast, packed lunches etc. Only make meals when you are going to sit down together to eat. He isn’t going to starve nor die of thirst; he will either miss a meal which won’t hurt him(!) or sort himself out - which is a step in the right direction. Secondly, I assume you do the shopping, therefore only buy healthy food - if he wants treats he’ll have to buy them himself. He should keep his medication by his bed, then it’s on hand. Once he is getting used to these changes, then stop organising his clothes for him.
Doing simple things for himself, that are perfectly within his capability should help his self confidence not undermine it.
If he doesn’t want to help with household stuff, DIY, gardening etc then perhaps you could go halves on paying someone to do the jobs you find the most arduous.
Hopefully, as these plans take hold, you’ll have a bit more “me time,” to take care of you!