I'm hurting inside.

Personally, I don't mind the paragraph type form, but at the same time I've never really seen those as poetry. It would work as a prose. But I'd suggest structuring this differently, somehow. Other than that it flows well, the words seem to go nice together. Of course when structuring it (if you do) then you might have to work with it a bit, but overall it's a good piece. Just looks a bit odd? But, oddness is okay sometimes, lol

"I cry for him, I can't bear the pain "

^^ I didn't like it that you're using so many fillers (I< you, and etc) right at the start of the piece, it broke the flow. Maybe:

Crying for him, unable to bare the pain.

"I don't want to hurt him, like others have hurt me. "

^^ Love this line, so much emotion packed into so few words.

" no longer wish to be here. I want to runaway with Robert and live happily ever after."

^^ I'm not to sure on the happily ever after, it's used so often that's it's become cliche, maybe try switching the wording up a little?

"Pain.
Hurt.
Hated."

^^ I liked this part, the abruptness really creates so many emotions for the reader and tugs at the heartstrings.

"Those are the words of my life. I can't bear it. I need him more and more each day. He's like a drug. I need him, I want him. I want him to kiss me. I want him to say he loves me for the very first time"

^^ I don't like the constant use of I< it throws the flow off. Maybe :

Those are the words of my life. Unable to bare it. Needing him more each day. He's like a drug. Yearning for him, wanting him. Hoping he will kiss me. I want him to say he loves me for the very first time.

"I miss him , It's killing me slowly. I need him"

^^ I'm not to sure about this, the closing lines seemed weak to me. Maybe something like:

Missing him desperately, slowly killing me inside, when will he realize I need him?

Or something like that.

That being said I liked the emotion in this, and I think with a little more effort could be a great piece.