Sounds like a terribly stressful time for all of you!
Who knows why these little guys do what they do. Some babies miss mom so much when mom goes back to work that they completely switch their schedule to nurse just when mom is home...it's called reverse cycle nursing. In that case, the answer for you is learning to nurse lying down while you are dozing and bring him into bed with you to nurse. That produces the least impact on your sleep.
I'd suggest you try two angles:
1 - it's the bottle/nipple. There are a lot of different nipples out there. Don't buy more than one, but buy several & just try one a day. I have seen the Breastflow work for a lot of breastfed babies. There's even one that is a complete one piece - Idiri. It's pricey so make that your last choice! (Both are available at Bosom Buddies website and stores.)
2 - it's how the milk is delivered, i.e. positioning, timing etc. For instance, some babies do better with a bottle when they are sitting up more; this can reduce the speed of the flow since there isn't as much push on the milk from gravity. Or, did you switch to a faster flow Avent nipple and he prefers the slower?
Have your husband try a little distraction: turn baby away from him letting baby's butt rest on his hip (the way we hold a baby to let them see away from us). Get him watching something, like out the window or (horrors!) TV, then slip the bottle in his mouth.
As an opposite approach, have your husband cuddle baby skin to skin with baby's cheek next to Dad's chest. Then try the bottle. Or wear your hubby's t-shirt to bed so it smells like you and have Dad put that on when he feed the baby.
A third possibility comes to mind: could it be the milk? Is it fresh pumped or frozen? What temperature?
Hopefully your son will figure it out soon, and I wish you the best. You are all giving him the best by hanging in there and continuing with Mommy's milk, so remember that it really is worth it for him.
S.