Don't want sex with my fiancé anymore!

Annie • Hi I'm Annie! 18 years young and I'd like to think very wise! engaged to my wonderful man ❤️
I used to be all over him, I'd always be turned on and always be the one to suggest sex..
But over the past few months, sex doesn't interest me at all, and my fiancé pointed out today that it's been a WEEK since we last did it.
As a sex addict, this is driving him crazy, he gets really frustrated with me.
It's not like we don't have the time to do it either, we always have plenty of time, I'm just never in the mood. 
Do you think I should just give him what he wants regardless of how I feel? I'm starting to feel really bad about it, and he feels like I don't find him sexually attractive anymore. 
I don't know what to do! 😭