I'm sorry, but you can create "new" memories in the house. Don't decide to leave on sappy sentimentality like that. Can he fully buy you out of the house at market value? Do NOT go with less. If he can't buy you out sell it and split the money. Also, you probably shouldn't buy anything until the divorce is final otherwise he'll have to do a quitclaim on your new place and he might seem really nice now, but things can change hugely during the divorce process. Almost every divorce I've seen gets super ugly over time... even when it starts off amicable. I know mine had some ugliness and eventually I did not trust my H at all!!! Money really changes people.
I understand when they are "done" they are "done." My husband was "done" too. Definitely DON'T hold any hope for your marriage. You do have to let go entirely. But that doesn't mean working on it and trying to save it wouldn't be your first choise. You can still start a new life while leaving the door open a crack. You just have to stop trying to look out that door at him, and convince him to walk in and give it a try. It's open, but he has to WANT to walk through it. It has to be HIS idea. You are not reaching your hand out to pull him in. You are too busy creating a new life for yourself. Focus on that. Definitely live your life like your marriage is over.
There is no arriving, ever. It is all a continual becoming.