My STBX and I have been living in the same house for about two months since we agreed to divorce. She finally found a place to move, but the lease doesn't start until September 1st. Living together in this kind of situation sucks. No doubt about it. It's a little better now that there is an end in sight.
I was pretty unsure about what I should be doing/not doing for her as well. For the most part, I kept cooking, doing the laundry, washing dishes, and most of the house work while she was out apartment hunting. I was pretty resentful of it (Doing all of the "domestic support" stuff just reminded me of what she was out doing while I was keeping her home and taking care of our child), but for the most part, I've adopted the attitude that if it's no skin off my back to do it (Does it really save me any work to separate out her laundry and only do my own?), then I should just do it.
In the end, I've come to realize that I have nothing to gain by making life hard for her. She's not going to feel guilt or remorse, and I'm not going to get any sense of justice out of it. She's just going to twist it around and make it about how badly I'm treating her. I can protest that she deserves it all I want, but it won't change the way she feels, so why should I bother? Honestly, it feels like less trouble just to keep doing chores and killing bugs for her than to try to make a point by not doing it.
So I help out when it's not too inconvenient for me in the hopes that it builds up a certain amount of good will that I can use in our co-parenting later on. I'm not going to go out of my way to make her happy, but I'll keep her pacified as long as it serves me, and I'll do it for that reason and that reason only.
As far as not saying the loud thoughts that pop into your head: Good. Keep that up. I had to learn the hard way that giving her a piece of my mind was a pointless endeavor, and had the potential to hurt my position as we headed for divorce. Be "good," and take the high road, and pat yourself on the back for doing it.
And count the days until it's over. You'll make it. Good luck.