I'm doing my best.
I know you are. I wasn't suggesting otherwise.
Not a helpful method tho if all it achieves is the ability to sit 2m away from your child rather than 30cm really is it.
Would you humour me on gradual withdrawal? Because I think it'll work for you.
You mention loads of different sleep training you've done in the two months since January. If you want to go the gentle route (ie not leaving to cry) then these will be the read on Gradual Withdrawal isn't as effective as it could be. It's the reason GW isn't progressing and is taking so long.
Gradual Withdrawal begins with trust.
The first principle, before anything else, is that of if baby thinks you're trying to sneek out and so do not give the reassurance she needs, she will try to stay awake.
If baby trusts that you'll always stay, then there is no longer a battle to stay awake. It shouldn't take a child more than 20 minutes to go to sleep. 5-10 minutes is more usual. If baby is taking an hour plus to go to sleep, and that child can settle to sleep easily, it would suggest actively trying yo stay awake.
You can reach your baby that bedtime means sleep time. That they don't need to fret or battle to keep you in the room, because you'll always stay close enough and long enough for their needs.
CC is fair enough for some families. But if it doesn't work and uou want to try the gentle route of gradual withdrawal, it will have broken the trust. This means a few steps backwards.
I'd start with leaning over into the cot. Firm hand to keep baby still. Stay there until asleep. Only once completely asleep so you sneek out ninja style.
Keep doing this until there is no longer a battle to stay awake. It might be a few days, a few weeks, a few months. But you should be able to get settling time down to 10 minutes or so, with lots of in-cot attentive reassurance.
Once settling tine is reduced (by trusting always stay and be attentive by actively reassuring her in the cot), then start reducing the reassurance. Say mean lean into the cot to settle, stand up once calm, lean back into the cot if upset, stand up once calm. And so on.
Once she trusts that you will stay right by here when settled, and come straight back if she needs you, she'll trust you enough to not create fuss to 'test' you'll come back. So the 10mins or so settling time is stood next to the cot.
Next settle leaning into the cot, step away when calm. Lean into cot whenever upset, step away when calm. Always go back needed? Always stay until asleep. It's about trust.
Then two steps away. Go back when upset or not lying down to sleep, withdraw when calm. Stay to sleep.
Maybe this is where you are already?
Next step is breifly (very briefly) popping out of sight. Have a job. "I'm just going to put this over here, be right back". Be literally only a second. Then wait. Reassure. Go back if needed. Extract when settled. Stay to a sleep.
Make the brief times out of sight more frequent. "I'll just put this towel back", "I'll just put this in wash basket", "I'll just put this in my bedroom, be right back". "Just popping to the toilet. Won't be a minute".
Maybe you go back in to his room to reassure when back. Once he trusts you'll always come back, he shouldn't need you to.
Next stage is promising you'll stay upstairs while he's going to sleep. Maybe put washing away or tidy the bathroom? Keep periodically poking your head around the door. In time you wont even neex to do this. It's just about developing that trust that if he happens to need you when he's going to sleep, that you'll be there straight away and give all the reassurance he needs.