I wouldn't keep telling him you're in a rush to divorce. That might make him think you'll be willing to concede more on financial issues to get it over with. Let HIM be the one that feels pressure from OW to get it done, while YOU have all the time in the world to make sure the settlement treats you and your boys fairly.
Also - now that you are realizing that things WEREN'T that rosy in your marriage for years before the separation - it's time to let go of some of the anger and start being grateful for the opportunities now available to you. I know this sounds like crazy talk - but trust me, the more you can open up to the idea of change instead of clinging to bitterness about the past, the better life is going to be for you and your boys.
And be really careful how you discuss things with your boys. The more YOU model strength and resilience, the safer they will feel (you are their ROCK). And the more you can teach them to look at their father's behavior with a modicum of understanding (even if it's just understanding that he's a damaged person), the better the chance of them healing their relationship at some point.
