I understand that he is your son and that he is family. Unfortunately, he does have a mental illness that needs to be looked after and treated by professionals. Schizophrenia is a serious mental illness and sometimes people with this disorder cannot cope in this world without the dependence of others. What might have to happen here is for your son to be placed under permanent psychiatric care. This is not to say that you will never see him again, you can see him and spend time with him any day that you like.
If your son is in permanent residence, you will never have to worry about him becoming homeless after your death or dying of starvation if he is unable to care for himself on his own. Depending on where he goes, he may even be taught how to reintegrate into society in a positive way while being semi - independent with a permanent caregiver.
Do not use this as a threat, but tell him that if he keeps threatening to KILL YOU, which is a very serious threat then this is how you are going to handle the situation. Sometimes, this is how you need to talk to a sixteen year old in order to get them to listen and sharpen up. Mental illnesses are a serious thing, we think we can help these people but sometimes it is simply out of our control because we are not professionals. I also tried taken care of someone with a serious mental illness on my own because I felt as a protector for him. Unfortunately, he severely used me and his condition to control me, so I had to eventually let him go and encourage him to get help on his own. All the best to you and I hope the answer comes to you soon enough. Make sure your son isn't controlling you in the way that I was controlled.
· 5 months ago