Help, Help, Help

My son will be 12 in August and I am in DESPERATE need of help with him. He is starting fires and doing very “strange” things. I cannot seem to get him to control his mouth. He screams at everybody. He lies insesintly. He started wetting the bed after being poty trained for over 4 years now. All of these behavior problems started after he had his open heart surgery. Someone PLEASE help me!!!