
we had a few really rough weeks recently surrounding this same issue. DS (22 months) was used to nursing all the way to sleep for naps, and I just couldn't do it anymore. I have no milk left, and it is just too painful. He was so tired but would just fight and fight sleep, and he won't just go to sleep on his own.
What we had to do was change his bedtime routine. Old routine-- nurse in bed, then DH came in and held him on the bed until asleep. New routine-- read books on the couch, the 3 of us "cuddle" in his bed, then I leave and DH holds him on his bed until he is asleep.
Then, I had to transfer that to our naptime routine. It took a couple weeks, and we had a few really rough days. But now for naptime, we do a few books, shorter "cuddle" in DS's bed (and sometimes he does nurse for about 10 seconds during this time-- that's about as long as I can stand it)and then I rock him to sleep. He fought it for a couple weeks, and it was taking me 30+ minutes of the rocking to get him to sleep. And I had to say several times "Liam, lay down and go to sleep." because he kept talking/playing/wiggling/crying, etc. But now he goes to sleep between 5-10 minutes. Oh, and we have to keep the room dark, with blackout curtains, and a white-noise fan. We have also sort of introduced a "lovey" (he never accepted one before) which is a blanket. He wants ME to wear the blanket as he lays on it while I rock him. It doesn't have to be a specific blanket, but just a blanket. Maybe you could try something like that?
For us the key was changing his sleep "cues" so that it didn't include nursing. Once he "got it" he doesn't fight it anymore.
