Holy crap, this OP post just reeks of teenaged angst, teardrops on your guitar and pure bullshit. Just because someone doesn't return your feelings, doesn't mean you should sit there, complain about them being your one true mate and generally being an all around entitled asshole. Sheesh. You make it sound like everyone who has had someone tell them "I see you more as a friend/sibling" after telling them your feelings about them should be an emotional wreck and is now being abused because they know your feelings and don't return them.
Dude, that's just creepy if you continue to pine after them, throwing yourself over puddles for them because you like them as more than a friend. That just shows that you're willing to become a doormat to gain any sort of affection from them beyond what you already get, which in turns shows them that you don't think yourself worthy of the effort to stay friends with them. Like you're some pauper glancing up at a castle from the village, wishing you could be on equal with the nobles.