Hearing problems are due to inflammation in the ear. So you need to take anti inflammatory drugs like ibuprofen and antihistamine. If infection is also there then use antibiotics. But it will be better to visit a doctor for prescription of the medicine.
The swelling indicates your system is trying to fight this. You know, for an ordinary sting I'd probably not worry, but the fact it's on the head worries me. You should call an advice nurse, either at a hospital or one your insurance company provides. They are usually available 24/7. I wouldn't wait. It's been 36 hours and I think normally it should be going down a bit. Did you put meat tenderizer on it? I've always had very good luck with that. It breaks down the poisons - or something like that. It does seem to work. Also, I usually make a paste of baking soda and apply that too, but these are things I do right away.
