dark room, heavy mind

[brandontoh]

The main thing here is about cutting the excess and making the poem more compact. This will give the poem more impact as a whole.

She once fell hard cause she dropped her guard -- Something like 'She once fell hard, dropped her guard' works as well. You can try rearranging the words and cutting the unnecessary ones.
unexpected end to what seemed to be forever -- Same here. 'Unexpected end, seemingly forever' or something along those lines. The poem as a whole feels like a first draft. Do try to take away things that don't contribute to the poem's image or serve no purpose. This will paint a clearer image of her.
once upon a time she didn't believe in but she believed in love
whats the word?
Every word to describe this feeling has been over used and no longer conveys the pain of her nights -- It's the same here. Do trim the fats. With poems like these, just the essence of each line is enough to get your message across.
Why is love so attached to pain?
shattered dreams -- This is a cliche, which you should try to avoid from now on. You don't want what you see in her to be generic right? Using cliches take away the feeling of uniqueness and specialness.
shes drowning and that feeling in the back of her throat intensifies -- This is good, and the imagery is strong.
overwhelming her once so wonderful soul
now just a shell of a person that once existed in this body -- But it leads into another cliche. Not that I don't get what you're getting at, but do try to use more novel expressions to describe it. Once again, cliches make things generic.
dark room, heavy mind
she whispers while avoiding the darkness of sleep
"Save me!"
"erase this memory I have!" -- These few lines are a borderline cliche. A simple rewording will make it many times better in my opinion.

Overall, a good effort. =) Just trim away the fats and sidestep the cliches, and you'll have a very nice piece. Hope to see more from you, and hope I'm of help!