I want more sex

So me and my fiancé have been together for 7 years. When we first got together just like every other relationship we had sex everyday even a few rounds in one day. It was that way till about a year then after it was just a few times a week or once a week, which I was fine with. Within the last year my fiancé’s sex drive just hasn’t been there and can’t even get off to porn 😒😞 so I know it’s not just me. Currently we have sex once a month or once every other month. I would love to have sex again every week or even every other just to start but every time I ask (yes ask 😣) I get “the look” or a sigh like it’s a second job that you dislike but you go cause you have to. It seriously makes me feel extremely upset and that I’m not good enough. I don’t know what to do? I have lingeries and sex toys so we can “spice it up” if needed it’s just not happening. I’ve brought the topic up but just keep getting the same answer, “Sorry”. Cheating is an absolute no as we’re always together except when we go to work. & we both are on each others phone (not like a crazy maniac thats insecure, just because I don’t wanna go get my phone or if it’s dead)

So any advice?