Also popping on to offer my support. I know it's so hard... I too get migraines from lack of sleep. Is your DH or anyone able to let you get a little sleep during the day while you work on this?
I'm also in agreement with cutting the daytime naps. As Sarah stated above, you could cut the morning one to 30min and do the afternoon from 1:30-3pm with a 7:30 BT. Or, as you know she can do one nap because of daycare, you could just go to one nap and let her sleep as long as she likes on days at home (up to 2.5-3hr if she's high sleep needs). The problem with the naps as you have them is if she's not tired enough to fall back to sleep when she wakes at night, no amount of sleep training is going to help her do that.
Here to hold your hand... I promise it will get better!