P.W.
Good advice from Love and Bettina below, the only thing I'm wondering is if it's your baby's noises keeping you awake, will that still happen if you hear her on the monitor? It's worth a try, anyway. I seem to remember keeping my first baby in his room early on, but there is a downside to that -- you can't just reach over and get them from the bassinet, you have to actually get up and walk, which if you're tired can be worse. Try the monitor and see.
Keep an eye on that depression. It could just be exhaustion, but if it continues or gets worse maybe it's time for a visit to the doctor. We're thinking about you.
p.s. - Are you breastfeeding? If not, why not have your husband take him nights for a while. With my third baby I decided from the beginning to do both bottle and breast so my husband could take him during the night from the beginning and let me recover.