Marital sex and complications.. 😑

So, my husband and I have never been particularly smart about sex. We got pregnant the first time we had sex together. And then I got pregnant again before my first born turned 1- THE FIRST DAY I missed my BC pill. So, I have an almost 2 year old and an almost 5 month old. I'm over having babies for the moment. I just turned 21, I'd like to be able to leave my house every once in awhile, and you know, NOT have to change 6 diapers at one time. But as far as protection goes, I don't have insurance anymore, my husband REFUSES a condom, and we don't have a lot of money for me to spend $30 on 10 tubes of spermicide. I don't know what to do. I just started my period for the first time a couple of weeks ago and I know I'm fertile right now. Obviously abstinence is there, but... I'm married and a housewife, my marriage is pretty much dangling by a thread at this point, I live in BFE with no friends or family near.. the last thing I'm doing is denying myself the one thing that makes me feel close to him.

What on Earth do I do? I cannot have another baby any time soon for sanity's sake and also for finances. And really, for the sake of my sad excuse for a marriage.