I would try going back to the crib. Seriously. My older two each stayed in the crib until they were 3, and the baby will as well. In fact, my son was not quite ready to give it up even at three. I think it provided a sense of safety and security he didn't feel in his "big boy bed". He began to wake up more and resist bedtime and when I suggested that maybe we needed to go back to the baby bed he agreed! So he had a little more time to mature before he was ready, too.
For what it's worth, we had a new baby before he was ready to give up the crib, too, but it wasn't a big deal. The baby slept comfortably in the bassinet and then the bottom of the pack-n-play for several months. When our boy was finally ready to sleep in his big bed the baby had no problem transitioning to sleeping in the crib.
Good luck! Sleep is too valuable to give up if you can help it--especially when you're getting ready for those sleepless newborn months again!