Can I lose my child if my fiance is violating his probation?

My fiance is on probation. He has 2 years left. I am thinking to turn him in anonymously to his P.O since he is violating his probation (using drugs) and i don't want him to be around my 4 years old son. I am worry about the police would try to get child protective services (I don't use drugs never have) I also worry they let him go free. I know i can leave the situation but he has me hostage in the house but not letting me use the car, he also threatening me to ruin my life if I leave. I trust he can ruin my life, he is mentally ill. Diagnosed with bipolar disorder he also displays personality disorders. I believe my only option to be able to break free from him is by reporting him.