Running Into an EX Boyfriend...

...can sure throw a girl off her game.
Everything was going along swimmingly in life. I ran into said ex-boyfriend in a totally unexpected, out-of-context location with his newest female friend. We exchanged our very short and awkward "How are yous" before I got the hell out.
Short back story: I met this ex in Europe while I was studying abroad. He lived 2 cities over from me back home in California...? Yeah, for that reason alone I thought he was "THE ONE." We immediately started dating after I returned from Europe and it was a perfect 4 months until "the catch" reared its ugly head...a drinking problem. We had somewhat kept in touch since the breakup and my mom had just been asking about him the day before the run-in. And now I can't get this night out of my head...
Anyway, do you ever have those days where you just feel off by an inch? That's been my week since the EX. I was an inch away from getting a job (a REAL job), was an inch too drunk after seeing the ex, fell an inch farther away from the guy I am currently dating, and was an inch off from going to the first Angels home game of the season and seeing a lot of old friends (but thanks to an extra cruel April Fool's joke, I didn't get to go). I don't know how to gain that inch back and I can't shake this overwhelming feeling of just being "off." I am distracted, irritable, on-edge and sensitive. PMS you say? I think I know myself well enough by now, and this is no PMS.
I turned to my all-too-accurate Google horoscope for some guidance. Part of it read, "For now, it's about listening to your emotional heart over your logical head." As vague as it may be, I'll take it. I need to stop thinking so hard about every little thing and enjoy the ride...