You cannot allow your emotions to dictate your actions. Let your rational head take CHARGE here.
If you really don't want to file, then DON'T! Stay the course by protecting yourself financially by speaking with a lawyer to find out what your options are. It does not necessarily mean you have to file for a D. These two are separate things.
H is miserable and wants you to bring you down to his level so he'll feel better about himself. Pay no attention to it. Leave him alone to twist in the wind all by his lonesome self.
You need to continue with GAL for your sanity's sake. Get out of the house. Don't answer his calls or texts unless it is an emergency. Show him that you will not drop every thing just to answer his desperate texts, calls.
If your H speaks to you in a disrespectful way, you need to put your foot down and state that that you will not be spoken in that way. IT IS UP TO YOU to lay down your boundaries.