OK. so. I'll get right to the point. I liked my old on-campus job in 2010 because it involved a lot of communication with foreign students, and I am pursuing a BA in second language (and might go to grad school one day) ... but due to chronic depression and insomnia I was frequently late and/or even a no-show at work.

I cried in front of my boss and told her I didn't feel worthy of working anymore. But she told me aside from my tardiness I was an excellent worker and that she knew how hard depression could be and that she suffered from sadness herself. She encouraged me to stay. I left after a couple months due to a busy class schedule.

Fast forward to 2012. I work at the library on campus now. The hours are greater but the pay is smaller. I started in 2011, when I was still depressed. I was tardy and absent a lot here too. My boss gave me a warning after graciously letting me stay here a year that if my attendance did not improve I would have to face suspension or possibly get fired.

This summer some new people were hired and we bonded so well that my depression (originally caused by loneliness) dissapeared along with my insomnia. These new friends were just what I needed to turn my life around. I started sleeping better and was able to make it to work on time and show up every day.

In the meantime, the office for my old job has moved from its old location to the office right down the hall from where I work in the library - so now, I frequently bump into my ex-boss and we've talked briefly and she smiles at me and things have gone pretty well I think - except for about a month ago when my new co-worker friends and I were having so much fun one day at work that we interrupted their staff meeting. She hasn't been as friendly with me since then. I realize now that I can't let my new-found optimism disrupt my professional work ethic. This is the first time I've felt happy in years, but I realize if I'm too energetic and crazy, I'll look like a fool in the workplace. I have to keep reminding myself that the fact my depression is gone does not give me license to goof off with my friends while I am at work.

And now, here is the tough part. The tough part is that I want my old job back. I will not be quitting the one I have, but rather, be working two part-time jobs. I want my old job back because it actually related to my future career, and now that my schedule has opened up and I am no longer a sad sack at work, communication with foreigners comes really easily for me. The new international student program starts in October so if I want my old job back, I have about a month to meet with my old boss and tell her I'm serious about starting fresh. But will my slip-up in the past month (back when I wasn't thinking about being re-hired) be reason for concern?

How should I approach my ex-boss? Her office is right next door and I could just walk right in... and I've been trying to dress more professionally at work lately, hoping she'll run into me again and see how nice I look, so hopefully she'll see that and it'll get her thinking. I'm worried she won't re-hire me. What do I do? am I just being paranoid?

I really want this old job back because they have an awesome summer work opportunity where they send you overseas for two weeks on an all-expenses-paid trip and pay you to tutor students English, and I would love to do this before I graduate in 2013/14. It would really be the opportunity of a lifetime if I got to do that, but for now if they hire me for the fall and spring semesters I'll at least be able to work locally with foreigners like I used to do, and get to know them and talk with them at our university (all while being paid).

Advice?