One of the sadest things about scizophrenia is that family abandon a very very ill person. It is very common for the poor people suffering scizophrenia to have no one
I have scizoaffective which means I have scizophrenic episodes and episodes of Bipolar 1. I have two friends with full scizophrenia and they have been abandon by all their family and outside of a mind support group have no one. I also have a uncle with full blown scizophrenia.
Its understandable that he doesnt want to spend his whole life living in care and please please dont abandon him as well I realise its not fair that you are now his only support network but think how hard it must be for him to be abandoned by his own mum for something thats not his fault.
You say he displays aggressive and violent behaviour, well as I get pychotic I understand this and I am able to visit the three I know while fully pychotic without any aggression or violence.
The reason for this is because I know what sets them off a few generic tips are avoid eye contact it feels threatening. Always try to position yourself lower than the person if they are sitting lie down. Try to apper relaxed as it is less frightening dont let any fear show. Dont touch him no matter what give him double the amount of space as normal but dont appear like you are shrinking away so stay relaxed about it. If he comes into your space dont back away or shrink.
Dont try and force him to get help just listen then call his cpn when you leave. If he is seeing things dont pretend you can see them and dont tell him he is seeing or hearing things instead say I know you can see/hear them.
If you speak to him when normal you can find out what generally his pychosis consists off. One of my friends thinks Barry manilow is trying to control her now she got very violent when ill and another user kept trying to put Barry manilow on.
I got aggressive because both my mum and my partner suggested at seperate times that maybe I needed a break and should go stay at my uncles. This made me think they wanted me out of the way and I became violent with my partner the second to suggest it feeling they were talking about me.
So speak to him and find out what his pychosis is so you can avoid it. Look into his illness if you understand it it is absolutly possible to see him and have a very low risk of violent behaviour. I hth if you have any other questions please ask me.