Wow, sounds just like what happened to me last night.
For starters, it is allergy season. There has been a lot of rain and the pollen is in a frenzy. Anyways, you never said you were rubbing it, so I guess that is not the case.
Last night, my eye stung and hurt so much I had to close it. My mother suggested something though, she said go to the sink and wash it out.
This is what you should do: Go to the sink AND MAKE SURE YOUR CONTACTS AREN'T IN BEFORE YOU PERFORM THIS, splash water on your face and while you are, try to keep your eyes open, once the water goes in your eyes, close them and go get a towel and dry your face and eyes that are closed. Open them and give it an hour or so, if it still hurts I really don't know.
ALSO! If after washing it it still hurts, wash it again so you get a good amount of water in your eye to cleanse it out.
I wish you the best!