#1 Protect your health. The body fuels the mind. You can't make good decisions when you let yourself go.
#2 Protect your career. There are lots of ways this goes bad, both in and out of your control.
#3 Lawyer up. Find the best attorney for the job with a proven track record. The money you spend extra will be a pittance if you don't do this. If your soon-to-be ex makes more than you do, then of course they'll recommend to "settle". Many states now award alimony without regard, so play that card.
#4 Don't feel bad, have remorse, or ever think you're doing the wrong thing by going the full monty or protecting your kids. Not. For. A. Second.
#5 And this is most important: Play to win. If you want to feel sympathy, remorse, pity or whatever remaining emotional attachment you may have, do so after you win. THAT is the time to be magnanimous.