Yep, I've been there!
I started having EXTREME pain one night, feeling nauseated, dizzy and just plain awful.
I figured out right away what was going on, even though I had never passed one before.
I had my son call the ER and they told me to come in but I didn't want to. So, it went on for a few hours and you're right - the pain is worse than childbirth - seriously. Then it passed and I happened to get it. It was SO tiny.... I couldn't believe something that small could cause so much pain.

Since then I drink more water and I haven't had any more.... I sure hope I never do.
Hope it goes quickly for you - glad you have pain meds to help you through.