You need to see an optometrist for proper treatment, but general rule of thumb is lubricating eye drops, that should help you out. You may be able to get some that have a pain killer in it, which is just a very low dose of lidocaine. To get the pain relief stuff that's really good, you need to see a doctor to prescribe it to you.
I saw one right after my injury 2 years ago. I was told to use "thealoz dry eye" drops. They are expensive but damn, they work like magic compared to the cheap regular eye drops.
Yeah, eyedrops are one of those things you can't cheap out on.