My plans right now are implementing a "blood pool", which is basically an invisible bar you fill up by drinking blood. You'll be able to store blood in bottles as a quick way to heal/feed, and you can sacrifice the blood you've drank directly to trigger immediate regeneration (sort of a self-heal spell).
(EDIT: It doesn't really matter actually but I'm leaving the idea here).
I can think of one way of doing that :
As soon as a character becomes a vampire, give him a new item such as a Heart (it could be his own, it might fit the vampire lore and he would have to keep it at all times otherwise he'd die).
This heart has 100 charges max when the blood pool is full. Then, through scripting, you can probably set the number of charges the heart has when the character consumes or gets blood and apply the according status.
Being really new to modding, I'm not 100% sure it's doable but that's an idea.
