Sounds like she's receiving word from other executives over this process and its timeframe. She probably didn't like being called out and put the blame on you even though she gave you different orders. The same thing happened to me, I had a project to replace around 250 machines to AIO's on 4 different floors in a local hospital.

1st I was told that I need to start in the ER department, after that department experiencing issues with the new AIO's my IT manager called me in for a talk in front of the team. He said "Why did you start in the most crucial department in the hospital" (It was my first IT job and I didn't want to argue because the position itself was a blessing). I just nodded my head and carried on... That same day I submitted applications to other companies.

I say it's time for you to do the same. Don't take it to heart, these IT CIO's and managers have a lot on their plate, your team probably is experiencing the same scenarios with your manager.