Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello,
In order to share your husband's Microsoft 365 Family plan, you still need to keep your Microsoft account, so that he can share it with your account, and you will use your account to sign into apps.
This is the instruction he can use to share with you: https://support.microsoft.com/en-us/office/share-your-microsoft-365-family-subscription-b389b9ce-3ae3-4a82-9017-39d79972fcba
So what you want to do is to cancel your subscription, not your account.
To cancel, go to https://account.live.com > Sign in, then go to Services & Subscription. Find the plan there, and cancel it there.
Your plan will still go through the rest of the subscription until the next renewal date. However, if you live in one of these countries, you can get prorated refund: https://support.microsoft.com/en-us/account-billing/countries-with-prorated-refunds-for-microsoft-subscriptions-38c81df4-10c1-f3eb-8d2f-b04f980c435f