Oversleeping and a broken circadian rhythm?

Hi! I've never had a particularly good sleeping schedule and I'm pretty sure somewhere in high school I broke my circadian rhythm to the point where it'll sleep as long as it can. I mean, I can wake up when I need to for class and work and etc but on the days that I don't have anything I can easily sleep 11-14 hours without waking. At my worst (when I was going through a major depressive episode) I slept 21 hours a day and let me tell you that was a crazy adventure.

I'm just wondering if there is an easier way to make it so I sleep a normal amount? Or reset my circadian rhythm somehow? It's just getting a little troubling in how I can sleep through most of my alarms these days (I own 3 different alarm clocks now just to make sure I hear one of them).