You're right, that's a crappy thing for someone to tell you in a text. Have you talked to him (on the phone or at least in IM in more detail) since that text?
Long distance relationships are hard - no doubt - but they are not impossible. I was in one for 2 years and 4 months and it ended with us getting married.
Some good points have been raised, though: you're changing - you're growing in your sobriety, you're (re)learning things about yourself, you're doing everything you're doing for school and your career - and he's not there to share that with you. That makes things more difficult. It doesn't mean you can't get past it, though. You just have to pay extra attention to the time you DO have together. Communication is oh-so-important.
I hope you don't puke, but I certainly understand what that feeling is like. :ghug2