9 Year old girl with Autism so angry and frustrated all the time

Hi there, my little girl was diagnosed when she was 5, she is bright and brilliant but over the last few months she is so angry and frustrated with everything. Even if you ask he a simple direct question it can set her off. We have always had meltdowns and social issues but we used to have periods of calm (ish). its so sad to see her continually fighting with herself she says she does not know who she is and its all too hard.

Any ideas