Buck up ****o! But, on a serious note, if she's explicitly said she does not reciprocate the feelings that you have professed for her then you probably aren't going to change her mind.
Some people would say just move on, friendships are only for using each other and if you can't use her for what you want (whether it be friendly conversation or it's drugs (I'm kidding, but I don't want this to come off as a "I use all my friends for personal gain")) then it's time to move on. Cease all contact, try again in a few months and maybe distance will make the heart grow fonder.