Do i still pay child support?

I am thje single father of three kids. Their mother and I are divorced. We have a 16 year old, a 14 year old and a seven year old. I only get the seven year old on the weekends. My 16 year old hates school and always has. He hasn't been to school in weeks and I was informed by the high school's guidance counselor that he will soon be dropped out. My question is this. Do I still have to keep paying the child support even if he isn't in school, and oh btw for those of you thinking that I am just another deadbeat trying to weasel out of paying, your dead wrong. My ex went out and had an affair with a guy that is in prison for attempted murder and is serving a six year sentence and I told the courts all this and they still gave my ex custody. I have very strong suspicions that she is spending the CS money on him and not the kids because my son never has on decent clothes, but ones that are way too small and have stains all over them when i pick him up. I need help in this matter, not criticism. Can anybody help me?