Mine was like this but then when he was 15 months I came down with a really bad infection that left me bed bound for a week with a high fever and chills. I was effectively quarantined away from my children and DH had to take over all childcare.
Befor, no one could settle DS2. Bedtimes, nap times, night waking - all had to be me. He would scream even more and louder if anyone else went into the room. Well, we just continued to always have me go in to prevent him becoming hysterical.
But then my illness put an end to that. What DH did was basically the Pick Up Put Down method. If he cried, he'd pick him up and just hold him until he calmed (which sometimes took a long time, but at least you're holding him. If he thrashed he was put down to calm down in the cot instead and a pick up re attempted after a few minutes). As soon as DS2 stopped crying (such sinking into DH's shoulder with exhaustion) he'd be put down. Cue more crying and another pick up ( and he should be put down and let go, not just nearly released) and repeat. The first night it must have been a hundred pick ups. The second night about 50, but by the third night it was only about 8.
I could hear all this from my sick bed and longed to just take over but was too feverish and weak. Just as well, because it worked. After that, not only could either of us put him down to sleep, but we can now leave him in his cot awake to fall asleep chatting to himself. He is 17 months now and settles himself at night. If he wakes, he sort of cries for 15s and then goes back to sleep. I only go in if it escalates to a bigger, awake cry. It means I or DH only go in if he's genuinely upset.
So now, he sleeps and settles well and it doesn't all fall on me. We do still, if he's distressed and we can't settle him, bring him into our bed - for example he's teething this week and has been in with us one night this week) but it's no longer the norm. And we can now tell he difference between "waaaah, where's my mummy, I can't fall asleep without her" and "waaaah, im really uncomfortable and my gums hurt, I need a cuddle and maybe Calpol".
So things are much, much better for us now. I'd say it took a full week for ds2 to completely lose the mummy insistence. He still favours me during the day and he was extremely pleased to see me again after my quarantine (melted my heart he did when our eyes met and his face lit up and he rushed over for a cuddle).
I can't say this will work for you, but it did work for us. We were forced into it by circumstances but I'm glad now that it forced us to tackle it.