I'm looking for a romance novel about fallen angels but i can't seem to remember the title or the auther.?

im looking for a romance book about fallen angels. they drink blood to heal but they can only drink from one women or they women they are meant to be with. they live in this tall building house and there is some kind of barrier about it to protect them for some kind of monsters. these monsters were once angels too but now they eat flesh. if i can remember i think azazel is the leader and in another book he leaves and finds his one that he's supposed to be with but its supposed to be a monsters of that kills babies because she can't a baby. and i think in the first book...im not sure what the angel's name is but he takes humans to hell. he almost takes his one that he was supposed to be with to hell. but the god...no it was another angel that the god trusties almost convinced this fallen angel to push her into hell even though she didn't do anything. she died from a car accident. she wasn't in the car she was walking. this girl was supposed to be the one that has some Special blood that can heal the fallen angels because the one they had at the time is with azazel but in the end of this first book one of the younger fallen angels betrays them all but opening the gates to let in the monsters and some of the fallen angels die alone with some of the women they had even the one that was supposed to be with the special blood. so the new one had to help them. and in the beginning their goal was to find lucifer. because god banished him and he was one of the first angels and banished him underground into a prison so the other fallen angels want to get banished so they can find lucifer. im sorry if this is all confusing. im just trying to find this book and im typing all that i can remember from the book. if anyone had read it before or have any idea what im talking about please help me. i just remember reading it from my friend on her ipod but i can't see her anymore cause she graduated. :< please help me. i must know what is the name of this book so i can read it again and collect them.