husband is ALWAYS tired!!

It's been 3WEEKS since we have had sex and every night I try to initiate it and some old some "I'm tired" or " I'm to old for sex so much", we are both 28 yrs old so we ain't old, and we already have sex only 2-4 times a month it's just going down from here. I just need to feel loved too cuz we have to have sex when he is horny which is always when in on my period and I don't like sex while I'm in the rag and he knows that so then he exspects me to give him my ass or a BJ til he cums.