If the Apple IDs for iCloud are the same all iCloud content will appear on both phones. The IDs for other things don't matter; only the IDs at the top of the Settings screen. And what you describe means that those IDs are the same. To unravel this you need to change one ID (probably yours, from what you describe. But you also want to preserve some data that is shared currently so try this:
- Do your phones have different names? If not, go to Settings/General/About - tap Name and make them different from each other
- Go to Settings on your phone. If the Apple ID at the top is the same as your husband's (it almost certainly is) tap iCloud, then turn off Find my iPhone. You will have to enter the Apple ID's password to do this.
- Next, turn off the switches for everything under iCloud. When you do this you will be asked if you want to delete the associated data or keep it. Assuming you want to keep all or some, say yes.
- When they are all off tap the Apple ID label at the top left. The heading should change to Apple ID. Scroll to the bottom and tap Sign Out.
- When the sign out completes, Sign in with your Apple ID.
- Turn the switches back on, and you will have iCloud sync just for your Apple ID, and anything you back up will be just yours.
- Now on one of the phones create a Family Sharing account that includes the other phone. This way you can share all purchased items. See: Family Sharing - Apple Support
After all this is done you can delete irrelevant data from either phone without affecting the other phone.
BTW, before Family Sharing came about a lot of people shared Apple IDs, and it didn't matter because iCloud didn't yet support syncing. it's only since the syncing features were added a couple of years ago that it suddenly did matter.