first of all I'm a girl so this may be difficult. But I'll say if you like her that much you wouldn't give up hope on one day you two being together. But if the girl doesnt like you it's not her fault, you can't control feelings. Just try and make her happy just as friends and see where that leads you. Maybe then she will start to like you and maybe fall in love with you. And just move on, don't know how but you know, haha.