I just used my neti pot to irrigate on my left nostril and my right ear started burning like salt on an open wound. what's going on?

Hard to know: If the saline solution is properly balanced, it should not sting. It will sting if the salt concentration is too high, but this may be exacerbated if there is irritation of the throat in the area of the right eustachian tube (tube that drains inner R ear). Whether solution reaches the throat sinuses depends on flushing velocity and head position. Using a squeeze bottle helps to control velocity.