Jealously or terrible two's?

I have Ashley and she is 2 years old. I am 14 weeks along with twins and she knew all about the twins and grew readily excited about them and would love to lay her head on my belly or kiss my belly and she can speak very well but has her issues with saying certain words. Now all of a sudden she stopped talking and is always throwing more fits and one day at her school, I was told she hit, bit and kicked two other kids. She is very well behaved in school. At home she goes into their room and trashes the whole room, takes clothes and other stuff and throws them or tries to rip them, taken bottles or pacifiers and uses them for herself or hides them. She now hates me and won't love on me and she was always with me before I became pregnant. Has this jealously thing gotten too bad that it needs help of a professional? I'm worried about my safety now because she has thrown things and it has almost hit my stomach. This has gotten to the point to if I go near her she screeches and starts flailing around and has once hit me because I tried to pick her up.