Several others have said it, but it really does come down to how you and your significant other negotiate your finances. I see how it's hard from your particular angle, since you don't have a salary and he doesn't have equivalent expenses...but there must have been some level of negotiation and recognition of the value of having you be a stay-at-home mom. Just because you're not directly pulling in money doesn't mean you're not contributing!! I'm sure you're already aware of all the work you do to keep the household running; while you may not be getting a paycheck, there is a very real value to that. In most relationships with combined finances there's going to be at least
some inequity in terms of who's bringing home what amount of money, but the point of combining finances in the first place is to look beyond that to how you can function together.
Now, keep in mind that I'm saying this as someone with a housemate rather than a spouse--most of our finances are separate apart from mortgage and other house-related funds, so it's never been an issue I've had to deal with directly. So take my advice with that grain of salt. But I think it might be time to negotiate, as
@Nakkira and husband have, a funds split. If you do that and your husband just lets his personal fun fund sit and does nothing with it, that's his choice. But I think it may help you if you both stop thinking of it in terms of a gift he's giving to you and work toward it being your own personal share of the family's resources,
to which you have already contributed by relieving him of the burden of all the things you do. I think it's healthy to have things that are just your own, and it goes a long way toward not feeling like you have to "justify" spending money on yourself. If it's in the budget, it's fine to spend. End of story.