T.W.
I certainly don't recommend letting your baby cry-it-out as some have suggested here, but it sounds like you already practice a healthy attachment for yourself and your baby and wouldnt take that route! :)
Instead, let me suggest a few books. My all time favorite sleep books. The one is Nighttime Parenting by Dr. William Sears and the other is The No-Cry Sleep Solution by Elizabeth Pantley. Both books focus on gentle parenting to solve sleep issues. How to help your baby fall asleep, stay asleep and not use your boob to do it. It addresses your child as an individual and helps you to focus on their individual needs. They are great and opened my eyes to how and why babies sleep the way they do and my role as their Mother to help them while still keeping harmony in our house and not inucing stress by letting them cry. Here are some links for those books. You can get them at your local library, or find them on ebay or amazon for cheap. Both books are endorded by La Laeche League and Attachment Parenting International, as well as William Sears endorsing Pantley's book.
http://www.amazon.com/Nighttime-Parenting-Child-League-In...
http://www.amazon.com/No-Cry-Sleep-Solution-Gentle-Throug...
Hope this helps Momma!