Perhaps you could approach it not so much as you taking over, but rather as a responsibility that you would like to share with your husband. If he is someone who likes to be in control (which is what it sounds like), letting you take over completely might feel like he is admitting defeat, or that he has somehow failed, which is not something most control-loving people are able to accept.

I would talk to your husband about working on your finances together. As another poster suggested, perhaps frame it so that it looks like you are asking him to help you learn something. Let him know that you are simply trying to be more involved in your shared household. Do not approach him with anger or with the attitude that he has messed up or let things slide, even if he has. Anger will not get you closer to your eventual goal, regardless of whether it is warranted.

If he continues to refuse to allow you access to the household finances, it does seem highly probable that there is something more damaging behind that refusal. I would suggest visiting the bank to look at your statements, or if your name is not on the account, trying to locate the statements when your husband is not at home. (NOTE: Snooping like this should only be a last resort - this type of behavior can exacerbate whatever distrust you might already feel.)

Lastly, whatever happens specifically with your finances, I would recommend seeing a marriage counselor. They can help you to learn how to communicate effectively about your finances and other things in your marriage, which judging from your statement about this being the latest in a string of situations, you and your husband would certainly benefit from. Money issues are some of the most common reasons for divorce, so try to resolve your issues, with help as necessary, before things get that far.

Good luck!