You need to dedicate a day to your daughter. This is your last chance for quality one on one time with her for a while. So take a day and do stuff she likes to do, and don't talk about baby at all, unless she brings it up. She can tell there's a big change coming, and if it's not something painful bothering her, she's acting out for attention. Smother her with love so that she knows she is still important to you.
I often find when my other kids are crying out might be due to ear aches.
Frustrating yourself gonna make it more difficult. Jus take a dip breath breathe and be yourself and try not to be confuse ur daughter may be girl cause of the baby u carry which may be a boy or she is in pain or hungry or tired. Play with her at time make her laugh but never frustrade yourself