What exactly is rock bottom?

i think this girl made me hit rock bottom when she turned me down because, i seriously thought she liked me but i guess she never did, i guess she just saw me as a friend, she made me feel so happy, but i didn't really want to show it of how much i liked her because she had a boyfriend and i didn't want to ruin it but i could hold my feelings in any longer so i gave her a rose and a card and a poem that i made myself for valentines day, i was so happy to see how she would react i was hoping that she would be happy but she looked as if she didn't care, she didn't really say anything to me after and she left a hurtful msg on her wall after she deleted me... now i feel like **** i lost that happiness, she was the only girl who made me smile