Is there a way to stop paying child support if your kids do not want to see you?

No; to the extent you want them to see you, arrange for counseling and get the help you need in this situation. They aren't kids but once and every day you don't see them is a day wasted, In my opinion.

No, it does not matter if their mother will not let you see them, it does not matter if they don't want to see you, You could ( although I don't believe in doing it) actually make them come and visit.. But you are obligated to pay for your child.

What are the reasons they don't want to visit, how far away do you live, had you prviously been seeing them on regular basis

No.

The only way child support can be stopped is if you relinquish your parental rights in order for the other parents spouse to adopt them.