I feel like Im always angry at my kids...?

Every day I feel like all I do is scold my kids. My oldest girl is going to be 12 and my son is 9 1/2. I also have a 2 1/2 year old girl who I feel like I am the only one who corrects her as well. I can't shake this feeling of that I just cant stand my kids. I will try to take them out some where to get away and by the end of the day im ready to explode.They just nitpick to each other so bad to the point I just want th strangle them and if I say to them that they cant talk too each other they will do it anyway and just get worse. I want to do fun things with them but im concerned that I will get there and they will start to bicker and I feel like I need to solve the problem then I get anxious and just end up yelling at them and the day get recked. it happens all the time. I try to explain to them how I feel and what is expected of them but there just is such lack of respect. I will say one thing and they will do another and play stupid then I get angry, end up yelling then im back to square one. I see people all the time where the kids follow the rules and the parents are happy and the kids are happy and I just want to be one of those people. It makes me so sad. what can I do so I can feel like I like my kids.