OP I had this exact thing last year, its a cyst/stye forming in your eyelid. Go put a warm towel (run it under warm/hot water) on it right now, seriously the longer you wait to treat it the worse it gets, I learned that the hard way, I had to get surgery to remove my cysts and at one point my whole eye was pretty much crusty puffy and shut. And I recommend going to the doctor asap, eye shit is no fun.
Super dope fun time.
(there should be a pic of my lovely eye problem to give you an idea of what can happen, but embedding is being super lame and not working for some reason today, unless I'm crazy)