Bunny .... your talk may have been calm but it doesn't appear to have given you any reassurance, and indeed, just a load more worry.
He is either incredibly stupid - and I don't believe that for one second with his job - or, he believes that he's this god-like person who doesn't need to worry about the "little" things in life such as tax bills, whilst your purpose is to bail him out and presumably be pleased to do it. How fucking arrogant he sounds (though he already did) when he talks about working to go on holidays ...... sure, if you can afford them, but not if you can't pay your tax. That comes first and the treats come after.
So ... just how is this tax bill going to get paid ? I suspect that one way or another you will end up paying. The normal swings and roundabouts of finances between normal couples such as replacing petrol you use will be declared as "impossible" as he has this "big tax bill coming up" and ditto him wanting to reduce input into the joint bills account (what the fuck ?!?) ... should you protest, no doubt the tax bill will be wheeled out again as his excuse for even more unequal contributions. Meantime, just as you've already been doing for quite some time, you'll have to make up the shortfall when all these fixed overheads have to be paid.
He is a complete and utter knob who is using you. I can't believe that if he earns at least double what you do that he apparently can't afford at least 50:50 into the joint account - and if he was a truly decent human being this would be a proportionate contribution. Nor can I believe - totally - that he has no money for tax. I can believe that even high earners can be spendthrifts but fancy car and holidays aside, does it not seem to you that there's a huge discrepancy between what he most likely earns and what sum he seemingly has at his disposal ? In the absence of further expensive spoilt-brat "toys" that he's frittered money away on, I would be very concerned that he's either a) stashing away "his" money so you can't get your "undeserving" mitts on it, or, he has an expensive habit of some description - be it drugs or gambling.
Fucking twat (excuse my language but I am so mad for you) .... "absolutely no need to know what he earnt" !!! How bloody arrogant can you get ? There's no need for you to know anything about his finances, but at the same time, you're repeatedly expected to pick up his tab in all sorts of ways despite earning far less and this entitled pig still says his money is none of your business !
There's every bloody need for you to know how much he earns. Not least, because if (god forbid) you end up staying with him you'd presumably like to know just how much of his liability you're going to have heaped upon you. Why the hell shouldn't you know ? He knows about your income - you're getting married - what makes him think he's so damn special and superior that you, a mere underling, aren't "allowed" to know about him ? Normal couples share their finances so they can make decisions about their lives and their futures together. So neither of them are placed at a financial (and emotional) disadvantage and so all essential expenses necessary for the running of their home can be paid. It strikes me that you're being kept at a very long arm's length here ...... it's not just the money he's keeping back, it's also a large part of himself .... despite being engaged - and even if you were to get married - he is NOT committing fully to you here. He's acting like you should be fucking grateful he's let you into his life and that he's so fucking fantastic anyone would be delighted to spend all their hard earned on him in order to keep him in the style he believes he's entitled to.
My god Bunny ..... no-one deserves this kind of attitude or treatment. You are a young (yes, 32 is young) woman who's obviously very clever, working for a well respected and decent firm in a well paid job. You don't need this total and utter twat in your life dragging you down. Is this really what all your past hard work has been for ? ..... so you can let an arrogant leech drain you not only of your money but all your self respect ? You are worth so much more than this and you have so many years ahead of you in which to build a truly happy life. There wasn't a single redeeming comment in what you've written above ..... his "promise" to set money aside for tax was immediately negated by his pathetic insistence on using what little tax money he does have on the holiday he "deserves". You can't trust him as far as you can throw him and his refusal to reveal his income and the way it was said was totally disgusting. His comment about the joint account was just as stupid and unrealistic as everything else that's been going on. He just doesn't "get it" one little bit does he ?
I don't see what is stopping you getting out. I do see - of course - that this is all tremendously upsetting, and sad, and disappointing - but there doesn't seem to be any hope in salvaging the situation. I know from past experience it's never "easy" to get out particularly when you have joint assets but I'm afraid that further hesitation will simply mean that this bloodsucker will continue to take just that little bit more for as long as you stick around. Far better to set the wheels in motion so you minimise his opportunity for doing that.
I'm sure that while your parents are worried and angry for you, they don't want you there any longer than you have to be. Any decent parent would rather their child was out of something like this sooner rather than later, regardless of the worry it caused them. I don't know if you told them everything but I'd be inclined to show them this thread so they can see the whole picture.
Please, please, do what's right for you. You should be absolutely raging at his treatment of you and his disdain for responsibility. Don't subject yourself to any more a minute longer than you have to.