3 year old girl and jealousy and emotional issues

Hello, i have. 3 year ols girl having atough time lately , nana has moves out of the house after leaving with us even before she was born, so i think she feels regected and resentful, also she is a tomboy which is ok but she likes this particular kind of sweat pants and have 4 pairs like its,,, the only ones she would ever wear, she will have amassive tantrum if i try anything else.... She also seems to be emotionally needy but when i come to give her attention he seems angry at me( as if she resents me for not givinh her attention while i was washing dishes)
She is struggling emotionally injust dont know how to help as she wont let me....
She is jelaous of older brother, loves animals, dogs, cats.... Doesnt like extreme temperatures like too hot or freezing cold although she struggles more with hot conditions
She suffers from constipation from time to time( i think is emotional)
And lives chips with salts, and sweets, loves chocolate....
Also he hair need to be done almost the same evry day or otherwise ishe wont let me do any other .... Andeebin bday parties or events she would look like a crazy child with a boys t shirt sweat pants snowboots i mean a mess , im worries about specilaly as she starts school soon and if i fare to put a dress on she will bring the house down....
She wasnt like this a year ago.....
She can be so happy and funny and cheeky but also although she seems confident , i think emtionally she struggles a lot, i almost feel as ifshe think i dont love her.... Anyway pls help!