The 2nd best advice I ever received in my marriage was be the spouse you want your spouse to be. The first was put God first. It doesn't matter if he/she deserves it or not. There were times when I was a complete selfish jerk but the unconditional love of my wife made me better because eventually your conscience catches up with you. Be friends again and find ways to laugh together, even when it feels impossible. And keep prayer as a constant in your life. God can change the heart of a king he can certainly work a miracle in your marriage.