dont have a neti pot?
try just using a small jug, or a drinking bottle(like kids or runners use with the sip cap thingy-sterilse it first with hot water then flush it with salted water)
hold your head on its side with the side the blockage is in facing up.Pour the water in(or squirt it in)it should flush out through the other nostril.
Or try getting in the shower and snorting water through the blocked side and spit-itll probably get flushed into your throat.