Just an idea...if you are worried about not having access to the account in case something happens to your husband, can you ask your husband to create a living will with you as the power of attorney? He can make it clear that if he is injured or incapacitated you would have access to the account. As for the worries about possible divorce, can you have a family member put some money in an account in their name and tell them it is only for safe-keeping in case of a separation or divorce? I don't know how close you are to your family so I don't know if that would work or not.
What I do (and it isn't easy when in the midst of hypomania) is to keep a small notepad and pen in my purse and when I see something I "need" (want) I write it down along with the store name and the price and make myself wait two weeks to decide if I will buy it. It is hard, but it works most of the time for me. It does sound like you've made a lot of progress with the spending and I hope you are able to overcome this last hurdle!
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From the movie The Hours: "If I were thinking clearly, Leonard, I would tell you that I wrestle alone in the dark, in the deep dark, and that only I can know. Only I can understand my condition. You live with the threat, you tell me you live with the threat of my extinction. Leonard, I live with it too."