I got a new boss at my last job and he wasn't very understanding of days I had to take off for appointments or school suspensions. Even though I made it very clear before I took the job that this would be an issue and they were more than willing to accommodate me. New boss didn't care. It didn't matter that I took work home with me all the time and they got much more than 40 hours out of me... he still wasn't very accommodating.
I was miserable at work and could see the writing on the wall, so I began looking for another job and I now have the best job in the world with the best boss. It's still difficult to juggle it all but she is very understanding about difficult child. Again, I told her upfront at my second interview.
Even if you don't want to get another job just polishing up your resume and even sending it out will empower you. At least you will feel like you have some control in the situation and if they do terminate you, you will already be in the game looking for a new position.
Linda