I understand you plight and your feelings regarding this. You do sound like you need a change but it does not have to be a drastic one.

Is there another bed in another room just you could sleep in for a while untill your son sleeps for longer periods?
Can you husband attend to him at night?
Can you give him a drink in a cup so no one is really getting all the way up?

Try to keep your idea of the family bed fluid. My husband slept with my oldest many nights when I was pregnant with my second. I slept poorly at times and needed to be let interupted when I did fall asleep. You can do it sometimes, part way and musical bed style and still get everyone's nightime needs met (especially if your hubby is wlling)

Congrats on the baby!