Well, my 10-year HS reunion is this fall...
but I ran XC and track (distance) for most of HS and, like you, did 3-8 miles a day and was in very good shape.
I did crew in college for all four years, but since I ended up as a coxswain (I'm short), I only ran during the winter for land-training... which was just a month or so at at time. Which was bad for me (even though I was on the ergometer often, it wasn't the same as running).
Since I graduated from college 6 years ago
I basically had the same problem as you, starting to run every day or every other day, and then burning out after a few weeks, or a month or two at best.
Up until this year... (I'm in grad school now), when I made a commitment to run and lift weights at least 3 days a week, and left it at that for most of the school year. I found it much easier to keep up my running habit for the entire year, simply by not putting huge pressure on myself to go at it every day. My bf and I sort of keep each other accountable, too, to this schedule... which helps a great deal.
Now, with my lighter summer courseload, I've been doing cardio almost every day, which can include running (often I mix it up with elliptical, ergometer, etc). After the last year of 3 x a week, I find going to 4 or 5 x a week much easier, and my body isn't freaking out like it used to.
So, I recommend not taking it so hard at first... just run a few days a week to get your body back into it, and slow down on eating gross cafeteria food and drinking lots at parties (if you do that). And I like Leto's advice... while you're arguing with yourself, get dressed for a run and lace up... that's the only way I can make myself get out there, somedays. I just let myself talk, but don't listen!
