Help with suddenly picky eater?!?

My daughter is 13 months old and until a couple weeks ago the best little eater I could have asked for. She would eat anything put in front of her and plenty of it. She completely transitioned off the bottle to a sippy cup around 8 months and we started making the transition to plates and utensils. We havent been pressuring her, just putting her food on a plastic plate instead of directly on her tray and providing utensils for her use. Things seemed to be going really well, she was having fun and we were enjoying the messy experience of watching her learn. The last couple weeks however she suddenly started refusing foods. She had never turned her nose up at anything before and now she refuses to even try things. She will only eat her few favorite foods; eggs, toast, cheese, milk, juice. Along with this came a few other rotten new behaviors such as crouching down on the ground and screaming till someone will pick her up, refusing her sippy cup and demanding to drink out of our gles, wanting to walk around with food instead of sitting in her high chair, and intentionally getting into things she knows she isnt supposed to be and making sure we know about it. Any advice?