I'm going to take a different approach than many of the others who answered. First, bravo for nursing so long and recognizing that your daughter still needs and or wants it for whatever reason!
My son is 28 months, still nurses-don't beat yourself up over this. It's really okay, despite people's issues with it. Every kid is different, every mother is different.
Mine co-sleeps, so it's a little different and he doesn't really wake to nurse anymore. Around 18 months though, I seem to remember reverting back to the waking. He's gone through all sorts of phases, practically weaning himself and then going back to it. Using it for comfort and making me the pacifier and actually seriously nursing. I'm not saying I've done everything right and I too have been through periods of absolute frustration. However, I am not a believer in CIO and sleep training and all these things. Some kids respond to that stuff very easily and for others it can be a complete trauma.
The easiest thing I have found if you want to start cutting it out and you truly are annoyed with the whole thing is to cut her off during the day first. All naptime nursing and sitting around nursing has to end first and talk to her about it. Let her know it's only for bedtime and that she's becoming a big girl and mommy's nursies or boobies or whatever you refer to them as are closing down. Use redirection as much as possible and when you start the nighttime weaning, replace it with bottles of water instead. It's going to be a struggle no matter what, but you can stand your ground as the parent and still be loving and gentle and not spend a fortune on books and methodologies. Most of our long term nursing friends have said about 60 days to completely wean. It's a process, it's not going to happen instantly. Keep in mind too that teething and growth spurts and anything that may be going on with her is going to fuel that want and need more than usual and this current phase may pass. I HIGHLY recommend not weaning during any period of health issues or changes in her. It will just make it worse on both of you. Enlist the help of friends/babysitters/relatives whoever watches or helps with your child. I find with my son, the more time he spends with dad or grandma the less focused he is on needing me and it helps.
I personally kept going because I wanted to get my son through all the teeth cutting-particularly molars and I just felt like he was a child that needed the extra attention. There's a lot of benefits to nursing as long as you have and taking your time to end it as well. 2 year molars are a several months long nightmare and nursing is one of the few things that has helped us through it.
You can do this mama, use loving words and lots of snuggles and hugs and redirection to playing singing etc to work through it. You don't need all this extraneous material, you just have to tune into what you and she both need and find something that eases you both through the transition. I wish you luck and better sleep very soon!