Hi D.!
This can be a very heated topic...to cry it out or not. Let me give you some info to help your decision. We all know babies cry. But what we tend to forget is that is their only way of communicating when all else fails. Imagine if your baby could talk. He said to you, "Mom, I'm real tired, but I just can't sleep. I don't know where you are, I'm all alone, I'm cold and I'm wet. Where are you?" Now imagine responding with entering his room, patting his back and then walking back out. He's gonna be like "Ummmm...Hello? Didnt you hear me?!" Studies show that when babies are left to cry, their stress levels rise. Then you become more distressed because at this point you are exhausted and at your wits end.
http://www.associatedcontent.com/article/19237/a_factbase...
It sounds to me like your issue really isnt "Should I let him cry it out" but rather "Help me find a way to get more sleep!"
Babies are defined as sleeping through the night once they can do so in a 5 hour stretch. Babies achieve this milestone at various ages. But when your baby wakes and cries, he is telling you that something isnt right. Go to him, nurse him back to sleep and go back to bed. Keep your baby close so this task doesnt seem so daunting. I dont know how you feel about bringing your baby back to bed with you, but I did that with all 3 of my kids and I have always gotten more sleep that way! I wake up refreshed and feeling well. Some babies sleep well on their own, some don't. Our job as parents is to make our kids feel good. Your baby is communicating to you that his sleeping arrangements arent working for him. So its your job to play detective and find out what works for him so that he feels right. Here are a few books that offer gentler ways at helping your baby establish good sleep routines instead of crying it out.
http://www.amazon.com/Nighttime-Parenting-Child-League-In...
http://www.amazon.com/No-Cry-Sleep-Solution-Gentle-Throug...
See if your local library has them, or even order them from amazon or ebay, used. You can get them pretty cheap. They are great books and have helped our family whenever we encounter a new sleep issue.
Also, here is an article written by Dr. Sears (the author of the first book) that gives you a basic tutorial about what the book says. It will at least help you understand your little ones sleep patterns a little better and maybe give a few ideas too! (if for some reason the link doesnt work, click on the red Dr Sears link on the upper right hand corner of the page...sometimes it doesnt patch you directly through)
http://www.askdrsears.com/html/7/T070200.asp
I hope some of this helps D.. And remember...breastfed babies need to eat more frequently, as you know. Dont be fooled by the formula society telling you he *should* be sleeping better by now. He sounds normal and healthy to me. Your only problem is finding a solution to getting more sleep yourself! Hopefully some of these resources can help. Good job Momma, keep giving him that magical mommy's milk!