"Unacceptable"

My son has been suffering with mental health issues for many years although has only been diagnosed recently. It has caused huge problems for not only my son but the whole family. We were very encouraged when he finally had a diagnosis of ADHD, depression and anxiety as we started to receive help, mainly from my sons High School who have been as supportive as they can of our situation. When the doctor made the diagnosis he prescribed various medications for our son and explained he would need to be monitored. This was fairly effective to begin with. The meds needed tweaking to manage the side effects and also ensure they were effective. However the doctor has since left and our son is no longer monitored. He has a mental health nurse assigned to him but it can be very difficult to get hold of her to discuss things. The nurse also is not capable of making the decisions about medication as this requires the doctors authorization. We have a social worker who has made some helpful suggestions but is rarely able to give the assistance needed and is also difficult to contact. My son has lost his place at school now because of his behavior, but fortunately been placed with a PRU thanks to the efforts of his previous high school teacher. Our son is overdue his check up where both his physical and mental health should be monitored (according to the doctor). How can the health service prescribe drugs so strong that they are considered a controlled substance by law and yet not have a capable person overseeing my sons safety?? As a family we now live in fear of the next time our son considers or attempts suicide. He regularly cuts himself and has attempted to hang himself more than once. We live in fear of the next time he smashes the house up and damages our property. We live in fear of the next time he attacks me. I have been bitten, punched, kicked, headbutted and left with cuts, black eyes and mental scars of having to restrain someone I love so much. His mum has needed hospital treatment after one attack made us suspect a broken wrist. She has had a cut lip, black eye but most of all a broken heart. Our family are a constant drain on the emergency services, our son has had a number of hospital stays and we have to call an ambulance or the police sometimes on a weekly basis. How can this be right? Surely there is someone who can help, and surely the health authority is failing greatly by not following up on my sons care. We are at a total loss and do not know where to turn. Sadly I know we cannot be the only family left to suffer this fate after the departure of the doctor. I just hope that help is made available before it is too late.