Creative and touching. It's a very nice poem. Just two suggestions.
Capitalize the second now here
"Now the lows have drowned the highs away,
now there´s no where else to go"
All of your other lines are capitalized at the beginning so this one is off.
And this line, which is one of the most important, is really long and throws off the flow of the poem:
"Black rose your thorns are cutting into me for the last time"
You should try to split it up somehow, or if you don't want to because it's a line that's supposed to stand out, than maybe make it by itself, with spaces between the lines before and after it.
My name is Mara and I'm seventeen. I've brown hair and dark brown eyes. Writing is my passion, though I like reading, singing, dancing, jogging and playing volleyball and soccer too. I mostly write in.. more..