How do I stop sharing my iCloud with my husband and get him a separate icl

Assume that you each have your own Apple ID.

Your husband can upgrade his iCloud, see this Apple article: Upgrade to iCloud+

Upgrade to iCloud+ - Apple Support

FYI: you can't merge multiple Apple ID accounts.

FYI yes you can leak your iCloud I have a back which my husband has his iPhone watch iPad Mac computer at my account that I can’t get into to close out my Apple ID that I haven’t used in years but I cannot manage to get into my Mac to delete my Apple ID iCloud