Is he on any meds at all, to mitigate his paranoia?
In a grim way, your description of him tallies somewhat - but I have to say far more intensely on your bf's part - with my own upbringing by a mum who probably had paranoid schizophrenia (it was never formally diagnosed - not that uncommon two generations ago) But I grew up with a mum who 'routinely' assumed she was being spied on, followed, spied on out of the TV, the house was bugged, there was a huge and insanely complicated 'conspiracy' going on about spies, and a complex court case that seemed to involve huge sums of money ,etc etc etc. I grew up assuming it was 'true', and it took a while to realise it wasn't happening at all and that actually there was NOTHING going on.
She could NOT be persuaded, or argued out of it. It is impossible to 'disprove' a conspiracy to a conspiracy theorist, even one that 'passes for sane' (!), let alone one that has genuine mental illness.
I'm not really sure what to suggest. My mum, for what it's worth, finally seemed to 'calm down' a lot in old age, and whether that was because she finally accepted meds (from time to time she went on Librium which turned her into a zombie), maybe the new meds were gentler?, or whether she was less stressed by other matters in her life, I don't know. She had quite a 'gentle' old age, and became a doting granny to her grandchildren, whom she adored. She was always 'a bit crazy' but in a far less destructive and dominating way.
But you can hardly wait until you and your bf are old, so really, I think it is a question of - sorry to be ruthless here - the following choices:
- accept him as he is (see below)
- fight tooth and nail to get whatever effective treatment MIGHT be available (and I have no idea if it is and suspect it isn't...that this is an 'incurable' condition, and can only be 'partially managed' to make him 'fit in' to any kind of society/relationship)
- end the relationship.
You don't say how long he's been like this, whether he's got worse, and what the docs are saying about whether it is either treatable or likely to diminish again for other reasons on its own.
If you do 'accept him' then I would strongly recommend you simply take this break ON YOUR OWN. And leave it at that. Don't take him with you. As you say, it will be hell.
What worries me is that you may not, sadly, be fully accepting of just how limiting your life will be if you live with him any longer. Are you hoping for miracles? I don't say that to be cruel, but to be 'kind in the long run'.
It might just be that sadly, however much you may love him, his insanity will cripple the possibility of ANY relationshiop with him. It already, doesn't it, rules out you having a family with him? (partly beause of the risk of any kind of genetic inheritance of his condition, though the jury, I believe, is still out on the cause of such severe insanity, and partly because it is quite unacceptable to subject children to a father with such a condition - believe me, I speak from experience!)(my mum was incredibly loving - and completely 'insane' - I can't really use any other word alas.)
Maybe I'm being too negative here, and maybe psychiatrists are far more hopeful of a better outcome than seems to have been achieved so far with him. I do hope so.
But it might just be that although you love him, you cannot spend your life with him. Nor he with you.
It's so, so sad, mental illness of any kind - but there it is. Bad things happen to good people.....not nice, but grimly true.
Have you had any counselling yourself? That might be a very good route to take if you haven't. This is a situation for 'experts' in dealing with him - you need ALL the support you can get.
Kindest wishes in such a painful predicament - Jenny