Help! I'm fed up with my Dad!?

He's my best friend...sometimes. We hardly fight....well until the past month or two! My mom had a hysterectomy and my Dad is going insane! Everything I do is all wrong and I'm only 14 but I'm extremely responsible! I'm the most mature in my family, almost and I'm the youngest! I love him to bits but I'm fed up!!! He says I neglect my Mama but really he leaves every single night to go watch a game or play cards or something! What do I do? I'm always with my Mama and now my once very close Daddy and I are drifting apart and it's all because of this! I understand it's very serious and I don't know how much pain she's in. I just know it's a lot. But it started even before the operation, really. It's driving me crazy! I miss him. How do I get through to him