Pregnancy and have a toddler

My daughter is 2 and we just found out we’re expecting baby # 2. For two weeks before we even knew we were pregnant she had been acting out horribly. She is normally very mild and well mannered but she’s like a whole different kid now. Crying at the drop of a pin, having angry fits, screaming and just being flat out rebellious. She only wants me most of the time as well. If I leave her sight she has a melt down. This is so hard I don’t know how to deal with it! Anyone else experiencing this? Any advice or ideas? Please help 😢 this is not how I hoped things would go and I hope and pray this passes before the baby comes.