what did my toe-ring do to my toe??

I've worn it for ummm.. about a year non-stop i guess. I thought it was sterling silver , maybe it's just tarnished- the color is changing. BUT this morning i woke to some discomfort- almost in the pain range to the toe. It is not noticable swollen, a bit reddish but not a lot. It hurts mostly on the bottom. I took off the ring of course.

Does anyone have any ideas then why it 'hurts' inside where the bone is?

Thanks for any ideas.