M.O.
My goodness I can hear your frustration! You poor thing! And newly pregnant too.
You don't mention how much your son sleeps during the DAY? I imagine he's exhausted too from all this nighttime activity. I believe a three yr old should be taking 1 nap a day, perhaps 1-2 hours. Don't let him sleep more/longer than that or he won't be tired at night.
Also, watch his diet. Maybe there's a food trigger/allergy that you don't know about. Stick with "God's Packaging" for most foods - whole fruits and veggies, lean meats, milk (poss allergy?) and whole grains. Limit ANY extra sugars, caffeine, nuts or potential allergens, like dyes, that may be making him hyper.
This is what I would do from here on out...and I too have read ALL the sleep books for problems we've had:`
1. After his afternoon nap, get him outside. Run. Play. Climb. Do anything and everything you can to get him good and tired.
2. Get him home, let him settle down, then eat dinner.
3. Start lowering the lights, household volume and NO TV.
4. Give him a calm, relaxing bath. Keep your voices lower too.
At this point he should be good and tired.
5. Get him dressed, read books and put him to bed.
6. Then go ahead with the "back to bed technique".
I realize you've already tried this, but stick with it. DO NOT talk to him. DO NOT negotiate. Just keep walking him back in his room, put him down and walk out. Be consistent. (Don't change, don't argue with your DH that it isn't working, this could take several days to a week to change this pattern.) If your son wakes up in the middle of the night, don't talk to him! Just walk him back to his room, over and over and over.
The premise is that he'll realize that he will not get anything from you and will go to sleep.
This of course is all based on the fact that he hasn't slept all day, and has a reason to be tired at night.
If Dad needs to 'be the tough guy' because Mom needs some sleep then so be it. Let him do it for one night or two, then you do it the next night.
Don't switch parents on 1 night. Be consistent. And don't engage him AT ALL. Don't change your "technique" or do anything different. He needs to know THIS IS THE BEDTIME ROUTINE. It's not changing. He's not making the rules.
I really feel your pain. We tried everything too. We too learned that being close to our child, trying to sit with her just made things worse. I don't think all techniques work for every kid. However I do believe that CONSISTENCY IS THE KEY.
Whatever you decide to do, STICK WITH IT. He needs to understand that these are the RULES and they're not changing (anymore).
NOTE: I realize that at this point EVERYONE is exhausted. And I know that you're looking for some "miracle". This isn't an easy fix. And it's going to take a little bit more of "no sleep" for you and your DH to fix this problem. So pick whatever ONE plan you like and DON'T CHANGE. Your son will protest, get up, yell, scream, cry, etc. Know that you are not torturing him. He gets plenty of love during the day. And your "turning off" your emotions at night isn't a lack of love...right now he's playing on your emotions AND exhaustion.
I wish you all the best.
I understand this isn't a miracle solution for you. This is something you've already tried - sorry. But stick with it.
It really sounds like you've tried everything else.