I hate 50/50 custody

Me and my ex have a daughter together. He cheated on me and left me another woman who he is still with. My daughter is 12 and goes to her dad's house one week. She's a complete daddy's girl and always has been even though her father walked out on us when she was 2 weeks old. I hate this man and want him out of my life. If it was up to me he would have no custody and it would just be me and my daughter. I don't like sharing custody with him. I don't like that my daughter is with HER half of the time. I don't like being a part time parent. The whole thing has thrown me into depression. He gets her this Christmas and they're spending Christmas with HER family. My daughter also got her period 3 months ago and NOBODY told me. I only found out because I found her used pad in the trashcan. Her dad got her some pads and that's fine but he kept something as big as her FIRST PERIOD from me. I'm her mom! I'm supposed to be a part of that. Plus he's not a woman so what does he know about helping her with that and I'll be damned if his whore is talking to MY daughter about HER period. I just hate this and wish I had sole custody.