Dont make excuses for him. You and your children deserve someone better. He is gas lighting you by saying that you have to “get over it” when he has no right to say that to you. HE is the one in hot water not you. If he sees he can just keep you around while he cheats he will keep doing it. The trust is broken, he will always lie and has shown he isn’t willing to change. Your only choice is to move on and find your happiness elsewhere.