I've been there.

Yes, we didn't have kids, so I pulled out. He was always holding his pristine credit over my head, along with the title to the house, cars, etc. that I "couldn't" have a part in, because of my credit past. $200 is dirt cheap for rent anywhere though... I'm currently paying half of $1910 in Massachusetts... (granted, it's a nice apartment, and it's Massachusetts, but my boyfriend never asks me to pay my half - I just do it for my own pride).
One solution might be to figure out what you both make, and you each pay a percentage of what you can.
i.e. total household monthly expenses (regardless of whose it is) = $1000.
You make $600 a month after taxes, he makes $800 a month after taxes. So you're responsible for 43% of the expenses ($428.57) and he's responsible for 57% of the expenses ($571.43)
That was the solution my dad offered up... it worked for a while, until a cutting remark when I hit a deer with his truck. "You did WHAT to my truck? Do you know how much it's going to cost to have that repaired? Couldn't you have just died or something? Then we'd get enough to fix it." I pretty much checked out of the relationship then and there. It's not like we were hot 'n heavy lovers anyway... more plutonic friends that were pushed together by his parents.
My current honey is such an improvement, I can't even begin to compare. He's just so loving and supportive in every way. I'm very lucky to have found him, although it bugs me that I'm now deathly afraid of the "M" word after the last one didn't work out...

But he understands that, too, so there's no pressure, and that's why I love him.

But I'd have never found him if I was still fighting over bills and crap with someone who didn't love me any more than a little sister to fight with and pick on occasionally.
If the money issue is the only one, maybe you should seek some therapy or a budgetting/mediator of some sort to offer up a solution that neither of you has a say about. It's never about one person - you'll both have to compromise.
--Janis