I miss my old dad

I just miss my old dad so much. He was always playful, spent time with me and my older sister and later with my younger brother but after my mom gave birth to him everything changed. He started to cheat, call whores when we were on vacation (he had his own hotel room, alone) and I am just terrified of him. He is aggressive with almost everything and once a month he is kind but I just cant fall for it. I feel so bad for my mom. My dad isnt even living with us anymore I could say, he is 37 I think and his new bitch he lives with is about 50 and is pretty rich. Everyone knows about it but I dont think he knows that we are not dumb to find out. I just miss him so bad. I havent touched him in years. Every time we even walk somewhere when we are on a vacation I look at his hand because I really want to hold it, I want to hug him but I am scared and disgusted.