Sleep training - Day one

I reached my boiling point this weekend and decided that it was time to get serious about sleep training. Lily was waking up every hour or so again and I've had enough. I'm not doing well on such little sleep and I don't like the person that I am at 3am. So, we started last night. I decided that my goal is for Lily to sleep 5 hours straight. My reading on sleeping habits for babies tells me that it is reasonable to expect that six month old babies sleep for 5-7 hours straight. This seems like a realistic time frame to me and while I'd love to have 7 hrs of sleep, I figure that I'll start with a dream of 5 hrs. So, Lily went to bed at her usual time of 7pm. As always, she woke at 11pm for a feed. After feeding her, I put her down and tried to get to sleep. Unfortunately, it took me almost until 12:30am to fall asleep, just when she woke for the first time. She cried for 15 minutes but I didn't go to her. We both fell back to sleep and she woke at 1:45am. She cried for about 45 mins this time but finally fell asleep at about 2:30am. It was awful listening to her cry for so long - I hated every minute of it. The trouble with "Cry it out" lies within the strategy's name. It's so incredibly difficult to listen to your baby cry and know that they just want you to comfort them. You feel very guilty about not responding to their tears but you hope that you are making the right decision by trying this strategy. Lily woke again at 3:30am and while it wasn't the 5 hours of sleep that I was hoping for, I decided to go to her this time. I fed her and put her back to sleep. She woke again at 5:30am, at which time Scott brought her in to me. After another feed, she went back to sleep but was up for the day at 8am. I figure that we all only got a few hours of sleep last night but I'm hoping that it was worth it as the first step in the sleep training. Lily was super tired today (not surprising) and had 3 long naps. I even managed to sneak in an afternoon nap. My book tells me that sleep training should take about 3 days. I sure hope so because I just don't know how long I can listen to her crying at night.