I wish I could address the finances/kids while still being the lighthouse. But pressing for D (or a legal S) does not feel like being the lighthouse.
Any vets out there have any advice?
Here is my opinion- this is a marriage-saving site and I am on board with doing everything you can to save your M. But after years here I am convinced that most people that end up here have full-blown WAS's and they CANNOT save their M. It's dead and gone by the time most make their first post here. The best they can do is let their M go and try to build a new R and M with their spouse. That almost never begins until AFTER separation. A lot of people here are scared to death of S because they think it's the end of hope, but in fact it's often the beginning of rekindling things. I'm not saying I recommend S, that's a personal decision. But I am saying it is not the end.
Being the lighthouse is simply being the place of strength, security and solidity when the WAS is anything but those things. Not just for your spouse, but for your kids, extended family, friends and yourself. In your case pursuing a legal separation for financial reasons may very well be a required act to continue being the lighthouse.