Get your toe cold, with ice.
I find it foolish and a little dangerous to force on a toe ring...if it's small to get on, it'll be even harder to get off....o.O
Maybe you should be worried about why your toe is swelled to begin with, keep an eye on it. Make sure it's getting blood flow. I'm sure it looks swell on you, as long as it doesn't swell you.
Put ice on your toe, than put oild around the ring. It should slide right on.