woke up with a swollen eyelid

Yeah insect bite can do this

Any other feeling? Like "sand in your eye"?

Also does your eye hurt? Can you move it in several directions without pain?

If you feel discomfort or pain when your eyes moves, it could be a sty. They're small points of irritation that occur on the inside of the eye socket sometimes.

Apply a moist warm compress to the eye a couple times a day.

Could be an allergic reaction, if it's not improving get yourself to a hospital in case it gets worse.

>>18625188
wash your hands frequently, avoid rubbing your eyes, and don't scratch your ass and then rub your eye in the future.