Why don't you pay him a rent from which he can make his contribution to the household expenses, including holidays and such, and the upkeep of the property. Look on rightmove for similar properties for rent, and agree to pay him half.
Don't pay anything towards the decoration or upkeep of the property (beyond the normal cleaning and gardening that a tenant would do). Obviously, you may want to buy furniture, but be clear on what is yours, I.e. dont buy jointly, and buy things that will be suitable to go in other properties (so don't pay for a built in kitchen, or wardrobes, for example).
He doesn't want to merge your finances, and so you need to ensure that you keep them very seperate, to protect your own interests.
You could continue to save, and invest in another property or other investment, to give you financial security in the future. (e.g. He might die, or you might split up, so you don't want to be totally financially reliant on him.)
You do need to seperate the practical from the romantic. You need to remember that marriage is a practical contract, designed to financially protect the partners, and the children of the marriage. It's also romantic, because the partners show they care enough about each other to afford
this protection to each other.
(Disclaimer - there are other ways to achieve this financial protection. But marriage is the simplest, and hardest to undo.)