Fiancés mental health is destroying our relationship

My fiancé went into her first episode of psychosis in September, the first two months I gave her absolutely everything I could in terms of support , I got signed off of work to avoid her being sectioned, it’s been heartbreaking to see , but now somethings switched .. and I’m at the fore front of her delusions and symptoms.

The paranoia she has around me is taking its toll, I have absolutely no time to myself .. if I talk to any of my friends that are female .. it’s “ you’ve taken a sudden liking to X “

She speaks to me like complete shit constantly. Last night she told me this is all my fault , I’m the reason she’s like this .

She will walk past me and declare how much I hate her constantly, the dog is petrified of her.

I sacked off the gym yesterday and took her out for breakfast to try and cheer her up, she was just as miserable and spoke to me badly regardless, I thought I’d surprise her with a nice home cooked meal for dinner .. when she realised I just got “ but I wanted that for lunch.. now what am I supposed to have “

I understand this is not her fault , we are still waiting for a solid diagnosis as to what is going on. But I am completely burnt out and this has put our relationship on thin ice , she doesn’t see that she’s sick, she thinks everyone else is the bad guy ( obviously no one is , it’s not her fault or anyone else’s ) She’s fallen out with her twin because of her demeanour , and they were inseparable.

Pretty much all of her family have given up on trying to help her . So it’s just me and her friends. And now I’m completely exhausted.

For context she is on meds , but in my opinion they aren’t working .. we’ve been fighting with the team to re evaluate her meds and it’s a struggle , our next meeting is the 13th.