Hi there @Steve3 ,
I'm sorry to hear about your son. It must be difficult to have these thoughts about what will happen when you move on. You are not alone. Many carers find themselves questioning this.
Does your son have NDIS? As much as possible, supporting your son to be independent is so important. Encouraging him to go out with social workers or support workers to start off with may be worth considering if he isn't already.
If your son is linked in with area mental health, it may be worth speaking to them.
In my area, there are continued care units (CCU) for people who need ongoing mental health support. In these units, people either have a unit to themselves, or they share with someone. Rent is a certain percentage of their income. There are doctors on site and nurses around the clock. They are specially designed for those who need longer term accommodation because of their mental health.
I wish you all the best and hope you are able to support you son in the best way possible. At the same time, don't forget your own mental health and wellbeing.
Take care,
tyme