Is it common for an elderly man with dementia to become obsessed with sex, and how do I keep from having my whole life controlled by that?

My husband is 76. His upper body strength is failing and he cannot even hold himself up to complete the act. But he is absolutely consumed with the desire to have sex, sometimes several times a day. He often can’t complete the act, but still wants to lie in bed and fool around for hours at a time. I’m 71 and have pretty well lost interest in sex. Mostly feels like a boring waste of time. It’s beginning to be a pretty daunting challenge to try to live life without managing it around sex attempts every few hours (often because he doesn’t remember we just had sex). If I knew he wouldn’t remember, I’d “just say no”. But when I do that, it sends him into tirades of worry, anxiety, and ridiculous accusations of infidelity. It ends up being easier to just “close my eyes and think of England”, but that too wears thin after an hour or so. HELP!! I’m going nuts AND feeling like a bad wife for even writing this. He wants nothing BUT me naked and available all the time. I’ve even been considering hiring prostitutes for him. You can tell, I’m losing my perspective. HOPE you have some thoughts on this.