Cry it out

I know, it sounds cruel, but today we are going to start conditioning Dillon to sleep on her own. Up until now, she's been pretty good about sleeping in her bassi for the first part of the night but then sleeps on me for the rest of the night. I allowed that because Greg sleeps in our room too and in order to get Dillon to stop crying, I would let her sleep on me.
Last night, I had reached my limit. After four days of being awake or semi awake between the hours of 1am and 5am, I am ready to let our girl cry it out and learn to self soothe and sleep on her own. I cannot have her sleeping on my body anymore as it gets hot sometimes or she moves or I move I don't know what but she gets up somehow. Is she hungry? I also need to be more diligent in my feedings I guess? Again, it's the whole "not knowing" thing as to whether or not she's getting enough food.
Really, I have no problem with waking up and soothing her, but I need her to sleep in her own space. She needs to learn.
Greg had reservations that 7 weeks might be too young and if you look online EVERYBODY says it's too young, but I just found some postings that support it. It saves your sanity! She is currently upstairs crying right now. I hope she stops soon...
Anyhow, as I'm reading Dr. Weissbluth's book, he gives anecdotes from mothers who have successfully sleep conditioned their children and in every single one the mothers talk about how much it hurt them to hear their baby cry. That it made them cry. Hmmm, does it make me less of a person that hearing her does not make me cry? I mean, it's for the greater good and I know she's not in pain. She just wants US. One woman's baby cried for two hours! I am hoping Dillon doesn't do that. I do not that it is breaking Greg's heart though...I'm sure he's online right now researching if it's too early to be conditioning. I mean, in my mind, we probably should have done this three weeks ago...