Their Trying To Impress Themselves

I ask because I'm really not sure how I feel now a days, my answer to everything is literaly 'I Dont Know'.
The thing is before, I used to be deliberately difficult and answer in a monosylabic manner, however now when people ask me a simple question I really am speechless, all that comes to mind is 'I Dont Know'.
It could be because my dad has decided to reintroduce himself to my family and is acting as if my sister hadnt died commited suicide.. Its quite sad really and depressing because we are all trying to accept it and move on but he is only bringing us back to where we were before, the thing is we i feel to shake him real hard and make him face up to the truth but i'm scared to because as depressing as it is having him here, it also feels so good, he now helps my mum in ways i could never have (i really dont want to think about it ...eww), its like the puzzle my family is, is slowly getting put back together, however we'd still be missing the final piece...
I feel so...lost??..I cant explain it.
Sometimes i feel as if I'm watching myself as opposed to being myself...I dont even know who I am anymore because whenever i try and get back to being me i feel as if i'm copying my sister but i feel like a crap copy as if i'm a disapoint ment to her, myself, everyone..
Now a days i dont eat, i cant eat. My belly would be screaming at me but when i look at food i feel...i'm not sure..repulsion.. i really hope this is a phase because i do not want to risk putting more strain on my family, it'll make them hate me even more..
I feel so pathetic and useless
Ugly and undeserving..
I'm sorry..
I'm not sure what for but i'm sorry none the less...
I feel as if i've done something wrong but i'm not sure what it is but i know its something real bad... I know i'm need to be punished and i've tried punishing myself but... i always get too scared...
The thing is i know that the longer i leave it the worst the punishment iis going to be..
This is all alot of babbling but it really helps to clear my head...
Does anyone know what I'm talking about..?