L.P.
Hi,
I also have an 11 month old boy who nurses. I have found the information in Mothering magazine to be really informative and helpful regarding breastfeeding. I recently read this article about the benefits of nursing past the first year: http://www.mothering.com/articles/new_baby/breastfeeding/...
Several health organizations, including the American Academy of Pediatrics, recommend nursing until the end of the second year. While your boy may be needing less nutrition from you than he did as a newborn, your milk is still important. Also, he's not using you as a pacifier....a pacifier is a substitute for you! There is still a very strong need to suck and to connect with you as he goes through all these changes. He's not trying to manipulate you. Of course it's comforting to have you there.
The idea behind attachment parenting, which includes sleeping with your child and nursing, is that the more you respond appropriately to your baby's needs, the more confident and independent they will be later. I have seen this to be true in my older son, age 12.
It is super stressful to go back to work, you're right! So this may be a time when nursing AND nursing to sleep may really help both of you transition.