I would personally recommend to just break off contact. It will just make you bitter and frustrated in the end,
unless you find someone else first. I've never been 'friendzoned' b/c when I find out a girl isn't interested I simply move on. Also when your interested in being more than friends, make it known early instead of letting it shimmer. I don't think 'platonic' friendship is possible when one is romantically interested and the other one isn't. Unless you want to put yourself through a whole lot of hurt, and why would you want to do that?
Similarly I had a...affaire for over 5 years with a girl I was really in love with(when you don't really 'have' someone it makes it that much more intense for some reason). We met every other week or so and everytime she declined letting this evolve into a serious relationship I decided to no longer see her. Ofcourse, like a fool I couldn't stop pursuing her and felt ecstatic everytime she contacted me. Then one day out of the blue she send me a short lousy email that she had ''found someone'' and that we could no longer see eachother.
Now, it might not be the most 'politically correct' thing to say but it just fucking pissed me off I wasn't that 'someone'. Made me fucking rage(eventhough she never gave me any false expectations). Espescially since I was good enough to pay for her rent, living expenses, studies etc. when she didn't have a job(again, something she never explicitly asked for). Deep down I knew my hope of us having a future together would eventually be in vain..but she was hot beyond belief and I just couldn't resist.
When someone is in it just for fun you keep looking for scraps of hope that just..really aren't there.
Moral of the story is and that I unfortunately found out the hard way: when you have feelings for someone and they don't exclusively choose for you(or reciprocate at all obviously), just run away. Preferably as fast as you can.