circadian rhythm problems

I just wanted to get a better understanding of what is going on with me. So with my situation... I worked at Disney World for 8 months and I definitely closed every single night. That mean I didn't get out of work until between 11pm - 2am. And it varied with the season. I usually got home 45 minutes after I got off work and then stayed up for a little bit and ended up going to bed really late. And late I mean like 5 or 6am. I wasn't tired when I got home so I ended up sleeping that late. Normally I would sleep until 2pm the next day and start all over.

Now that I'm back in school, my body is having a major crisis or something. I have to get up semi-early, like 10am. I think my circadian rhythms had been completely reset when I was at Disney. I seriously did not feel the slightest bit tired until 5 or 6am, and even as late as 7am. Now that I've been trying to get back on a normal schedule like 12am - 9am would be nice.... its been absolutely horrible. I want nothing than to go back to a normal schedule. I feel like crap constantly, like my body hates me and just feels "bad" or "sick" and I don't know why. Does this have something to do with the rhythms? I don't know how to fix this. Usually I stay up late, get up early, and I can't for the love of god prevent myself from taking a nap during the day. Once I do that, the whole schedule is reset again and I once again cannot fall sleep that night and the cycle repeats itself. It's been a month, and I still can't get back to normal. But I heard it takes up to six months to fix?

Is there any escape? I do not want to resort to taking medications I don't believe in taking them!