I too am in the UK my dBPDh has a co-morbid dx of schizophrenia. Where one thing ends and the other begins I do wonder. My husband takes antipsychotic meds and there is a massive deterioration in his overall functioning when he has stopped taking them.
Our experience of mental health services has gone from really good to downright disgusting over the last 10 years. If you find a psychiatrist who understands BPD and is good, follow them to the ends of the earth.
Good support from your local CMHT will be absolutely vital in helping your partner navigate and understand his symptoms, medication, behaviours and early warning signs of crisis.
It's interesting that you read 'manage him better' I actually said validation can help him 'manage a bit better.'
I'm pleased to hear that you will still go on holiday next week, it took me a while to disentangle myself from my husbands chaos, but once I did breaks away have been really great. My son and I are off to Paris this evening for a weekend break, something I would never have done before finding this site.
Enjoy your holiday.