You don't "cure" it.
Carefully remove the stinger; don't use tweezers, because it can cause more venom to go into your skin. Use a dull butter knife, and scrape at it in the opposite direction from the way the stinger went in; this should push the stinger out of your skin.
Make a thick paste using meat tenderizer and a bit of water; apply this paste to the sting. It will draw the poison. (This also works for scorpion and jellyfish stings.)
If you are or think you might be allergic to wasps, GO SEE A DOCTOR IMMEDIATELY.