You admit to being 'quite fussy borderline OCD' which suggests that, deep down, you know that a lot of your fears are irrational.
If you genuinely want to live a happier and more relaxed life then you need to find ways to dial down your anxiety, not enforce your anxiety-driven expectations on your husband.
Speaking as one germophobe to another, the only thing you have mentioned that is a rational concern is not washing hands after using the loo, because of the possibility of fecal contamination. Even here, I'm sure many men will be quick to point out that when they're doing a wee, they've only touched their willy and the flusher, and that you have nothing to worry about!
No-one is getting ill or dying due to not wearing toilet slippers, re-wearing clothes that have touched the floor, or sleeping in undies. Your reaction is excessive and is not adding anything positive to your life.
I have a friend who recently split from his wife, and one of the reasons was being completely worn out with his wife's contamination-based anxieties. Constantly being given instructions about changing clothes, washing hands, not touching this or that, not allowing bare feet to touch the floor, etc etc - she had a justification for every single one of them. He got to the stage where he simply couldn't take it anymore.