go to amazon and buy cooperative parenting and divorce. it is a good simple to read book all about learning how to coparent.

first rule, you don't want to be yelling. it means you have lost control. you are not going to get anywhere. the focus needs to be on meeting the needs of the child. if it gets away from that topic, it needs to be steered back to that conversation. were talking about activities for the child, and someone brings up child support, we need to redirect the conversation to activities or we could get into an argument. treat every encounter like a business meeting. the child is your business. leave emotion out of the conversation. you are there to discuss the needs of the child, nothing else.

most of the time, an argument is based on your beliefs of what the child needs and not the childs actual needs. you may think the child needs a red coat and you will fight to death for a red coat and your coparent will fight to death for a blue coat because you have been raised to believe that red and blue are the best color coats there are. in the mean time, your child is freezing to death because she just needs a coat. she doesn't care what color it is. so you need to learn how to identify what the real issue is without your belief system attached to it because parents generally fight for their beliefs, not the issues.

you can pm me with specific issues if you want. there is really too much to put in one answer here for you. take care.