My advice is different from most of the others. And it's real simple-----where is the problem?! If he ever, at any point, slept 5-6 hour stretches, consider yourself lucky. Sleeping thru the Night is only considered to be a 4-6 hours stretch anyway.
IT IS NORMAL FOR A BABY, EVEN AN 8 MONTH OLD, TO WAKE OFTEN AND NEED HELP GETTING BACK TO SLEEP.
Ask yourself what bothers you the most, his current sleep habits or that you *think* he should be sleeping better. If you could totally block out what others moms, books, society has to say on how babies should sleep, what would you do? Continue to go to him when he wakes? Continue to nurse him at night? Probably so, as this is what is instinctual.
I've been coming to mamsource for a few months now and I continue to be outraged at the number of moms who encourage Crying It Out (CIO). The first year is all over the map. There are so many "firsts" in this year, so many phases, sometimes they sleep good, sometimes they don't. Nobody ever said a new baby was easy so why do we expect these new little humans to sleep like adults.
I am strongly against CIO. But you gotta do what you gotta do. Breastfed babies are especially more likely to wake at night. My good friend said it best when she said "I don't ignore my 8 year old or my 16 year old when they need me at night, why in the world would I ignore my infant, who does not have the words to tell me what he needs!"
I can tell you that I breastfed my now 2.5 year old on demand, he slept in our bed, he woke often and slept little during the first year, we never let him CIO, basically we did everything 'society' tells you not to do. Now he sleeps like a log and rarely wakens.
I think his eating habits sound fine. Breastmilk should be the main source of nutrition right now anyway.
Here are some links on normal infant sleep. You'll find out real quick that this "sleep problem" is normal and MOST babies and moms are going through the same thing.
8 Infant Sleep Facts Every Parent Should Know
31 Ways to Get your Baby to sleep and stay asleep
(without using CIO!)
Newborn Babies and Sleep
Sleeping Thru The Night
Studies on Normal Infant Sleep