Honestly OP, don’t waste your time explaining yourself any more.
It sounds as if you have a sensible, knowledgeable GP who recognises that prescribing a tiny amount of benzos for use when you hit crisis point works for you. And that actually matches the NHS guidelines for prescribing. If your use was escalating or increasing I’m sure your GP would put the brakes on but it doesn’t sound as if that is remotely the case.
Talking therapies don’t always work. It sounds as if you manage your mental health 99.99% of the time so there’s absolutely no indication for SSRIs etc.
Much as PPs may disapprove, benzos still have their place in medicine when used with care, which sounds like the case here.
Propranolol can be good for dealing with the physical symptoms of an anxiety crisis like racing heart, shaking hands etc but might not have enough of an effect on calming your mind. They also typically can’t be taken if you have asthma.
Personally, if occasional benzos work for you I wouldn’t worry. You and your GP are both happy.
But you do need to figure out your DH. Taking your medication - and using it all - are huge red flags that he has a drug problem that he can’t control. And this might put your benzo prescription at risk. What he did isn’t ok - I’m glad he’s having to tell the GP what he did but that might not undo the damage. Trouble is, if he won’t accept he has a problem, you’re going to get nowhere.