I was going through something similar, but was only pg with DS, he wasn't here yet.. And we went to sleep school and things got worse. DD lost all her trust in us. and we had to build her trust up again.

Sleep school works for some, not for others, and although I am not against CC in some situations (and have used it myself), I just couldn't handle the sleep school way of doing things. Maybe your DH could take leave (am just assuming that your DH works, sorry if not the case), and have a week, where you work on her sleep, and if your DH is home, you and him can take naps in a tag team so that you are both a bit better rested to accept the battle.

If you want some more details on my sleep school experience, I am happy to PM you with it..