I have a 2 year old and a 5 week old and my new little one is similar, I had a midwife tell me that after bub has dozed off on the breast pass her to your hubby and get him to rock her to sleep then place her in whatever it is you want her to sleep in as she won't smell your breastmilk. It worked for us in the first few weeks. I also ended up getting an electric breast pump to feed BM via a bottle through the night and on the boob in the day, it really helps! but thats if your into doing that, he only has a feed at 2 am and then I put him on the boob in the bed at around 5 am then we get up so its only one bottle a night but it gets him through until a decent hour and I get two 3 hour blocks of sleep. hang in there!