Sex life taking a toll on marriage

When my husband & I were still dating our sex life was amazing. We would do it any time of the day, in the car, he would surprise me with sex, a ton of foreplay - I loved how spontaneous he was. But ever since we've been married our sex life has gone downhill. Especially in the last year or so. I'm lucky if we have sex twice a month. I'm a very sexual person & practically have to beg my husband for sex. He has had a lot of health issues in the last 6 months so I know that has somewhat to do with it. But I don't know what to do anymore. I feel like I annoy him because I'm always asking him for sex or making sexual innuendos. I offer just to give him a BJ and he declines. It's really lowered my self esteem & is taking a toll on our relationship. We've tried talking about it, but he just says he doesn't know what's wrong with him & that it has nothing to do with me. I've tried lingerie, tried porn, just about everything. I don't know what to do anymore & it's driving me insane. Any advice? 😔