Hi, I am only 26, so i might have a slightly different perspective. But I also deal with thoughts about suicide. Not exactly now, but some day. I just dont want to wait until i am old and physically suffering. I am not a diagnosed Schizoid, but i have obvious traits, and also I am an INTJ.
In my country (germany) assisted suicide is legal. Terefore we have associations for assisted suicide, that will help you to kill yourself. I don't know the exact procedure, but you will have to pay at least 50€ to become a member for 1 year or 500€ for a lifelong membership. Also you need to justify your motivation so they see that your will to suicide is not just a short-term emotional eruption. There might be some other small requirements.
This is propably not the best way to avoid any social interaction, but a good way to avoid long periods of suffering in a hospital or whatever. Also such an association has the required experience to make shure nothing goes wrong.