Is there some way to make it that I lose 30-ish hp/second while in vampire lord form? Can I do this with console commands, or do I need a mod?

Why I want this:
In Requiem, vampire lords get a 600 max hp and stamina boost. I still want to keep it as a "ultimate ability" where you are super strong, but with a pretty massive drawback, so that you have to use it at the right time.

You'll need a mod. Create the magic effect that drains health on self. Creat spell with said effect and choose your duration+damage amount p/s. Fire the spell via a script attached to vamp lord form. On effect start, drain spell active. I don't think there's anything else to it.