Major eye problem and pain plz help ?

We were at the beach this morning and basically my brother threw a bunch of that sand with little shells in it at my face and my eye was open when it hit and a ton of it got in my eye. I was wearing contacts when it happened btw. I couldn't open my eye for abt 5 minutes but I got some of it out so it didn't hurt when it was open. I got home & took my contacts out 20 minutes ago and i can't open my eye and it hurts really bad. it hurts if there isn't pressure on my eye so I keep one hand ovr my eye. I typed this with one eye and ionesco hand on an iPod touch :P but it hurts really bad and idk what to do. We can't afford to get an eye appointment so what should I do? I've already rinsed my eyes with water but it didn't help.. thanks so mch