2 year old has become so angry and tearful all the time

[user1464795209]

Hi everyone . My daughter is our second child and she's was two in October . The last I would say 3 weeks so has been so angry all the time and tearful almost constantly . She has gone from
Being caring and sweet to refusing to say hello back to people and screaming 'no' and 'nothing ' to somebody even saying 'hello' I have no idea why or what's caused it . She strips for no reason watches our reaction and then screams and cries for ages and ages . This happens all day long . I have been ignoring it in hopes she will see it gets no negative atrention . I also have offered hugs etc which she screams more about .
She appears so rude and her love of life has disappeared over night as she just cries and screams at everyone . :(
Any ideas ?
She's not poorly btw x

*strops not strips

My son is 3 and this happens very often. I would say one day from 2-3 looks as yours, for so many months:)
We are from Russia, and there is a term in Russian children psychology - "crisis of 3 years". This is the time when children realize that they have personalities and can say NO when they want. And they use this option:)
The only thing that helps us is validating emotions. I sit near him, look in the eyes and say: "You are angry because you don't want to dress up, right? You scream very loud, seems that it is a really unplesant for you". After it the child starts to listen to me and even answer something. In some cases it helps to avoid a tantrum, in some - just gives a little pause and I can turn his attention to smth else. I believe this is a natural process of nervous system development and we'll survive it.
I can also recommend My First Emotions, it is a resource for children 0-3 years old, it teaches children to cope with feelings and helps parent to deal with such situations. We use it, in UK it is also available at www.skylarkenglish.com.