Watch your back, OP. He may have something devious planned. Jk in all seriousness, you should probably have a talk with him about how he's making you feel. He's not being completely fair to you.

drug him and take him to get the vasectomy done.

I sincerely hope he was joking. If not, I strongly suggest marriage counseling.

Why wait? If he's already done living life to the fullest with you and is panning his future relationship with someone else, good riddance.

I strongly suggest divorce. this guy is a total shitheel and shouldn't have kids in the first place if this is his opinion on marriage. clearly he's living in the fourteenth century

This isn't a healthy relationship. While he has the right to refuse to have a vasectomy, he's being unfair and kind of an asshole if he expects you to stay on hormone birth control forever; especially since, unsurprisingly, birth controls aren't safe as you get older. If he's refusing a vasectomy, and you need to go off BC (and it sounds like you do) you can go off birch control and inform him that sex is no longer a thing. That said, it sounds like you really may need to just GTFO of this relationship before he becomes any more toxic. Seriously, it sounds like he's already got his next 'bride' picked out.