So do french fries. You don't see me swallowing them down whole every second of the day, do you? It's not good for you. You keep drinking human blood and you're going to die. Someone will hunt you down and they will kill you.
We should try cow. You could eat beef when you were human, right? Can't be too far a stretch. I knew a vampire who fed off cow once. A whole pack of them survived that way, actually. Called themselves vegetarians. It's too bad I don't know where she is, she'd probably be better at this than That's what you need to become.