@anonforthis88
I feel so low mentally. I NEED some spare time!!!!
I honestly feel your pain, OP. Have come back to this thread hoping that little one was settling down a bit better but it seems you've not had much luck thus far 😔 so sorry to hear this.
I appreciate that this doesn't apply to you as your little one is not even 2 yet, so still very young. But my DD has been running rings around me recently when it comes to bedtime.
After having read like 3 stories, singing 3 of her favourite lullabies, dealing with her complaints about her leg that she said "hurts" because she scratched it on something earlier (didn't bleed), moaning that she's not tired and doesn't want to go to sleep (even though she's been awake since 5:30am with no nap today), moaning which turned into screaming and kicking her legs against the bedpost, shouting through the monitor that I'm a horrible mummy and she wants a new mummy, blah blah fucking blah ...I am absolutely at the end of my tether.
So I decided to do something I saw DH do the other night. She has this plastic table with two chairs that is in the living room for her meals throughout the day. I took one of the chairs and placed it in her bedroom at the end of the bed facing the wall, and every single time she moans, starts giggling and trying to talk to me through the monitor, complaining about minor irrelevant things, I placed her on the "naughty chair", facing the wall, not in the dark mind you, with the lamp on. And told her when she's ready to go to bed, to let me know through the monitor.
We repeated this process (I kid you not) 17 times before she finally got the message and stopped messing about and now as I type this, I can't hear anything through the monitor so I can only assume that she is asleep (will go and check on her in a sec).
I don't know where I'm going with this but ultimately, it's about setting rules and boundaries. I appreciate your DS is only 20 months old though so such rules/boundaries would obviously have to be tailored for his age.
I'm not a fan of the CIO method with very young babies, I think it's cruel. But where he's at an age that he understands to a degree (I saw an earlier post of yours where you said that he went from crying to laughing once he was playing with his toys or something) .. that tells me that he understands to a degree what he's doing in terms of "if I cry and scream loud enough and for long enough, someone will come to comfort me".
So in conclusion, I think that you need to try your best to be a little more stern, drop the DH cuddling him to sleep, and slowly but surely, distance yourself in terms of going in so regularly to check on him.
I would use CIO to a degree to begin with (as long as you're not aware of any other health problems he could be experiencing) and see how you get on.
Apologies for the long post and best of luck OP 🤞