What can I do to stop this?

So under my right eye it's a little bit swollen (only a little bit, it's hardly noticeable to other people) and everytime I touch it or sometimes when I blink it hurts. At first I thought I was just sunburn or something because I'd just been out in the sun alot and was already burnt but I'm pretty sure it's not now because it's not red or anything. It just hurts on the bottom lid from on of the corners to around the middle and it's not the eye from what I know, just the skin. What could it be?? And how do I stop it from hurting and getting for swollen?