Boyfriend doesn't want to have sex

so we used to have sex several times a week. now just a couple times. which I'm ok with. that's not the point. But today on our lunch we planned on sex and now we are both home and I mentioned that I want to have sex and wanted to shower and get all sexy and he denied we agreed to fuck tonight and I reminded of him of when he said that and he had this look of dread and was like "ughhhhh" I DID say that...m and now he wonders why I feel completely unsexy and undesirable. there's nothing worse to turn you off than to be made to feel like a chore to fuck.