I hear you! :) I was worried about my baby (4.5 mos) falling asleep while nursing, too.
The only sleep book I own is Healthy Sleep Habits, Happy Child by Weissbluth - my aunt & uncle gave it to me when my LO was a newborn, and I've had a love/hate relationship with it haha. I'll read it until I started feeling stressed out, then put it down for a week... then pick it up again...
Overall, it's helped me learn more about how important sleep is for your child, no matter the age. It has some helpful advice, and a whole bunch that I tossed out the window, too. But one of the "comforting" things I read was that babies who breastfeed to sleep rarely have issues with this as they age. This from a doctor who advocates CIO (he calls it the "Extinction" method lol) and who has done a ton of research on infants and sleep.
Anyway, I figured if a guy who's ok with putting your baby down and letting him cry for 2 hours is ok with letting your baby nurse to sleep, that's good enough for me... maybe that's twisted logic, now that I actually type it out... but it's what worked for me lol.
One of the other main things I took from the book was to keep baby up no more than 1-2 hours at a time!!! And another was also just to be consistent with how you soothe to sleep as your baby gets older. We used to hold our baby pretty much all day long and since we cosleep, he's always right there by us. This was great when he was tiny and could sleep like a log in the store, in class, doing dishes, etc. but he got to the point where he wasn't sleeping well. Like you said, my baby was only catnapping all day long, and obviously craving more sleep. If we tried laying him down though, he'd just wake right back up again...aaah!
What we used to do:
Hold baby (in arms or sling)
Bounce/walk/sing/rock/jiggle/shush/nurse/give binky/repeat! to get him to fall sleep - sometimes all of the above and he STILL wouldn't be asleep. We'd also have to do this in the middle of the night and be up for 1-2 hours @ a time...killer when he's been up every 2 hours to nurse for his first 3-4 months anyway.
Constantly play Pandora/lullabies station if it's during the day or have our air purifier on full blast for white noise in the bedroom
Plus we had lots of meals whispering the whole time until a fork clinked too loudly, then it'd be back to jiggling and shhhh'ing
Bathtime right before bed
What we do now:
Naps (only when baby is starting to look/act sleepy, generally at the 1-1.5 hr point) - nurse, read 4 books in the same order, swaddle in muslin, kiss good night, lay him on side facing away from me with pillows wedged beside, give him binky (which he usually spits out as he's falling asleep), pat bum and shhh til he falls asleep.. if he's good and tired it only takes a bit of fussing, then he's asleep in less than 5 minutes...
Night - bath, nurse, he falls asleep, lay him on side with pillows wedged beside.. generally, he wakes up 2-3x and requires more bum-patting and shh'ing, or for me to pick him up and rock him back to sleep, or @ least til he's sleepy enough he doesn't protest much (a couple minutes of light fussing) until he's out again.
Gosh, that seems really complicated when it's all written out, lol. And truthfully, it hasn't been easy! My LO gets MAD...! But he's been sleeping sooo much better and is such a happy boy because he's been getting more rest. AND I can actually do stuff while he's asleep.. (we're moving in 2.5 weeks and have almost nothing packed!! I need to get stuff done!)... so while it's been hard, also it's been wonderful having this new method. Seeing great results within the first couple of days really helped DH & I to stick with what we started. :)
I would have loved to completely avoid the whole pacifier thing, but I was his pacifier for his first 2 months, and it was wreaking havoc on my poor boobies (I really struggled with oversupply..among other things). Thus, the little binky... and I would've loved to have been able to continue wearing baby for naps til he was too heavy any more... but it just wasn't working for him to be around me/DH as we went about doing things that had to be done... homework, laundry, etc. He wasn't sleeping well during the day and consequently, wasn't sleeping well @ night.
Haha, as Weissbluth says, "Sleep begets sleep!" :p It's so true, tho - if my LO doesn't nap well during the day, he has a crappy night, too - which makes all of us cranky. :)
Hope that helps a little.. sorry for the boatload of details, haha. But that's what's working for us!!!