I sometimes wonder what I would do if my family disappeared, which will happen one day, I think it might be a major threat to my mental health.

It's hard to be sure but you sound a little paranoid (thinking people are against you when they're not) maybe they really are against you, but you should ask yourself if you are imagining it, it's possible they really care about you.

It doesn't mean you are "crazy", most people start to think weird things when they are stressed and have no-one to talk to and bounce ideas off, I do it at 3 oclock in the morning when I can't sleep and there's no-one to talk to, this could happen to anyone when they loose loved ones.

If I lost all my loved ones I think I would get involved with helping other people, volunteer work maybe, to stop me thinking about myself and my problems.

Just getting amongst people, shopping, cafes, bars, buses or something more interactive like an evening class or friends, puts me in a more realistic frame of mind, takes my mind off my (sometimes imagined) problems.

Good luck