Because sweetie, that's life. These dramas...they don't go away. Even in the most perfect seeming families, there's always stuff going on beneath the surface. It's true for me, it's true for you, it's true for everybody on this forum, it's true for everybody in this world. Drama happens...most of it happens within families. And it will never go away.
Good for you that you don't tell anybody about the little stuff that goes on everyday. Good for you that you're trying to put it aside.
Focus on the positive in life. Try to let the little stuff go as you've been doing. But don't become a doormat when it comes to the big stuff. And move on. How do you do it? You just do it. You get up every day, you find ways to keep busy, you have fun with your spouse and your friends, you make dua and say your prayers. It isn't easy letting stuff go. But you have to make an effort so that it doesn't weigh you down and plague your life.