M.P.
I had this same problem with my now 4 year old (the paci was taken away at around 14 mos). We didn't have the option of giving it back to her, as her favorite paci wore out and this particular paci had been discontinued. She would have NO substitutes.
One thing we did (and still do!) is lie in bed with her and lightly stroke her back and hair and play soft music. Usually, this puts her right out in about 5 minutes or so. But then you have to master the art of getting out of bed undetected. :)
I have to say it was a struggle after the paci went away at first and got better slowly as time when on, but this ended up working best for us. I hope this helps you!