Yeah, firstly, assuming you're engaged to a guy, it's fiance.
Secondly, stop being such an idiot. You're not with your ex boyfriend who sounds like an asshole, you're with presumably a man you love and want to marry.
Thirdly, if your relationship is so amazing, you should be able to talk to him honestly and clearly about the fact that this is bothering you. You will be likely combining your finances at some point anyway, and will need to talk about who handles the money, who pays the bills, that sort of thing. This is a good opportunity to discover how well you two can address challenges together.
Lastly, I'd be shocked if he "hated" you for needing his help now and then. If he loves you, then he likely wants you to be happy and will do whatever is necessary for that to happen. If that means he pays for your car insurance or buys the groceries, so what?
If it helps at all, I have a little story for you.
I've been married almost 13 years and I recently used my husband's and my joint bank account to buy a birthday present for my mother. (This joint bank account is only funded with my husband's paychecks). I meant to use my own credit card but didn't have it with me. I planned to transfer funds to cover the expense because the joint account is supposed to be for groceries and gas and dog food. I told my husband what I'd done and what I planned to do and he looked at me in shock. He said Why would you transfer money, do you think I'd get mad and say you couldn't buy your own mother a present with my money?? He was laughing!!
So stop thinking you're any kind of burden to your fiance, and remember that most people, especially those who truly LOVE us and want the best for us, are always happy to help us.