Riding the sleep train

I did not sleep train my oldest son. I went through the first year of his life in a dream like state, subsisting on catnaps and coffee. I truly couldn't bear to hear him cry and so I ran to his every whimper. The truth is, he was probably annoyed. Like "why does this chick keep coming in when I roll over?" We would sometimes rise at 4:45 for the day and I would be totally on board. The truth is....enough coffee can make anything tolerable. And so, with my second son...I have fallen into the same pattern. Run to him at every cry...although in my defense, he and my oldest are sharing a room. So, it is more about keeping the oldest asleep then about setting some sleep boundary. It wasn't until my pilates instructor recently informed me that I would not lose the last 10 pounds of weight until I slept a consistent 6-8 hours a night, that I made the decision to sleep train. Call me selfish, call me vain..you'd be right. A sister can only wear maternity clothes for so long. So after juggling people around, in order to keep the night owl isolated, sleep training has begun. Night one, went as expected...lots of crying and wailing until exhausted, sleep came. And that was me. No really, there were long stretches of crying and I swear I could hear him say "mommy...please come to me". It literally killed me. My youngest son, is the only male in my house that loves to cuddle. Part of his sleep problem is that he wakes up, realizes he's alone and cries out until you come hold his hand. Once he can feel you, he falls immediately into a peaceful sleep. Knowing that he just wants to be near me, makes sleep training so much harder. I feel like I'm totally alienating him and I'm desperately afraid that this will turn him into a non cuddler. He will shut that part out, because sleep training will have taught him that no one cares to come to him when he's lonely. I try to remember what my best friend said. "Its better for them to get the rest." I know this is true and I deeply appreciate the extra hours of sleep I am getting, but the guilt that fills me when I turn off the monitor will haunt me in my dreams.
The second night of sleep training was better than the first. He only woke up three times. Twice he cried and I went in, gave him his pacifier and after a brief whimper, he went back to sleep. The last time he woke was to eat. This may not seem like sleep training, but if you knew what the last 7 months have been like, you would see this is a MAJOR improvement. Night three has been the worst yet. Not only night 3, but day 4. Its as if, he now knows the deal and he's not going down without a fight. Every time I set him in his crib to nap (which he has always done happily and willingly) he has cried and grabbed onto my hand. He settles down after a few minutes, but it isnt the gentle, peaceful lull into nap that he has previously enjoyed. Last night he woke up many times and when crying didn't bring me back, he decided to just stay up and jibber jabber to himself. While this was cute to hear, it made me so sad. Is he so lonely, that he is keeping himself company? Imagining he is jabbing to another baby perhaps? Needless to say, we were both exhausted today and neither of us is looking forward to tonights festivities. If its anything like last night, I may just need to suck it up, buy bigger pants and enjoy a life of co sleeping with my cuddle bug.