@Felicity I’m glad you posted, you shouldn’t feel like you need to hold back on sharing whatever you feel like sharing 
Gosh your Dad’s been doing well on his own in his home, although reading between the lines it sounds like you are practically living with him and ensuring he can…as @Chris_22081 has termed it, some of us have experienced the poo-nami 
issues and cleanup, so BIG empathy for him and you!
I’m sorry to hear he had sepsis/kidney issues @Sue24’s husband also had sepsis which can be really problematic to resolve. Geez Covid can really frustrating on its own but then impacting your dad’s medical investigations must have been a worry for you…he’s sounding scared and stubborn from how you describe your Dad…my Dad passed at 79yrs of age and he was cantankerous (to say the least) and threatening all sorts of things at worst, when we had to call paramedics… So I hear you!
Perhaps the wisest thing to do right now is check on what he DOES want, do you feel able and okay to have a conversation about his care and wishes for when something serious happens? It sounds like he’s already been making his own mind up about what he wants and doesn’t want so openly asking him for his thoughts can trigger a difficult but clearer alignment for you both
Postcode lottery is awful. I’m glad that the nurse is coming for the anticoagulant
If it’s not too distressing have a read of what I wrote on a post fairly recently - I’m not suggesting that your Dad is at this stage but the links and resources could help YOU, understand what’s possible…I really hope that’s I’m not upsetting you. My Dad was adamant that he didn’t want to go to hospital which made me worry about what I could and couldn’t do IF something happened
both @Charlesh47 and @bowlingbun had some additional wise words of experience to add in those posts about local resources and process, plus very useful thoughts as always
really hope I’ve bot overwhelmed you with all that! From the daughter of one stubborn father to another I feel for you!