frustrated and tired! HELP!

Jasmine
Key points: my LO is 15 months as of next week, Still nursing, (has only had bottles at daycare) we have co-slept since she was about 6-7months. (Single mom, don't judge)
For the last week she has woken up screaming if I don't nurse her back to sleep. It's an issue now because before I could give her the paci, she'd whine a bit but be back tosleep in 60 secs. Now if she even hears me reach for it at night she screams and cries. I'm trying to not nurse her during the night as a first step to transitioning her to the crib. I don't know what to do at this point. I'm frustrated and tired from lack of sleep if I don't give in. I'm torn between giving in and nursing her because I know that comfort is what she wants, but I don't want to encourage the "tantrum" that she throws because of not getting what she wants intially. On the other hand I'm not comfortable with the CIO method which is why I thought a slow transition would be better. I don't know what to do at this point and could use some advice or opinion from a fellow mommy!