I'm not able to take hard decision - Separate from her

I'm thinking hard these days that why am I living with her. Even if I hire a maid, she will take less money and will do whatever I will ask her to do. I know this is bad thinking, but I'm not happy with her. 

I have seen girls who fights with in-laws, others, BUT not with husband. And, she fights with me. The reason, only known to her. 

I started feeling that she is having some mental issues. Her anger is too much. Kids are also facing this. Everything is going well, then all of a sudden she made the atmosphere worse. She is a master of this.

I keep thinking of separating from her, and thoughts of living separate with her. It feels good, but thinking of kids made me sad. 

I tried talking to her father. But, he is such a useless person. He did nothing, instead he tried making me understand. I was so pissed off. Now, I'm in no mood to talk to anyone. I will now make a decision (If I could), and just convey them.

When will I get that courage?