Hi C.,
I have three amazing kids that are all out of the pre-school era. I can tell you that I didn't have a clue how to get my little ones to sleep thru the night until my third.
I understand the frustration, heartache and exhaustion that you are feeling. My son was just the same. I tried to have him "cry it out" and it ended with me crying from my bed while he stood in his crib screaming "Mommy, Pease. (please) Mommy, pease." Honestly, it's not good for either of you.
You and that bottle are your son's way of being comforted during the night. Let me ask you this... do you put him in bed already asleep? Do you rock him first? Rocking a baby is a wonderful, bonding experience, BUT always put them to bed awake and never let them sleep with a bottle. Two rules that work on a newborn, but can take a lot of work at your stage. A child who goes to bed awake knows and understands where he is and how he got there. One who is rocked to sleep has his last memory of being in Mommy's arms and suddenly wakes in his bed, jolting him from his comfort zone.
I'm just a Mom, not an expert, but I want to share the process that worked for me. It's tough to do, but well worth it, especially on that first full night's sleep. (If you even remember what being rested feels like:)
Step One: Put him to bed awake. Drowsy, but aware of his surroundings.
Step Two: No more bottle or pacifier in bed, and never get him up to give him a bottle (sick babies are the exception.) AAAHG! I know it feels like your only sanity right? It's really a disruption. Once he loses the "Bink" out of his mouth or "needs" his bottle, you're getting up again. So brace yourself for the resistance and be tough.
Every time he screams, cries or tantrums, go to his room and lay him back down. Say to him your "command sentence" gently but firmly "It's time for sleep, son. Night, night Mommy loves you." (That's what I said) He will freak-out, for lack of a better term. Don't bother going to bed... just lay him back down and leave. Don't wait or watch him... leave the room. give him a few minutes to fuss and do it again and again and again. He will get tired and eventually fall asleep. This took me a week. Every single night. Have Dad help with the process so that your son understands that this change is from both parents.
You need to sleep. Lack of sleep contributes to weight, problems, depression, low immunity and various other terrible things.
Good luck to all three of you.
D. B