Sorry to hear that Phatferd, as like h0rt and boomer I can definitely commiserate. I can sometimes remember the day my last ex-girlfriend broke up with me, a few days before Christmas 2004, and it took me oh, almost 3 years to get over the relationship and to get over her. We weren't technically engaged, but we agreed some day we would marry. Long story short, it became a long distance relationship because I had to go back home after my year-long study abroad in France was over (we met prior to this when she studied abroad here in L.A.). We could cope fine long distance from L.A. to France because we were once used to talking online a lot. However, this all changed after she moved to India at the beginning of the new year to run away from problems at home. We couldn't manage the time difference to talk to each other, she was wrapped up in her new job, and one day, she said that was it.
I was devastated. It wasn't as if my life sunk in paralysis, but I was slipping into severe depression. I was so depressed I never got drunk to drink away my problems or sorrows (in fact I had gone about a year and a half in pledged sobriety), let alone to open myself to dating again or to go into bars looking for girls. I couldn't be arsed around to get into casual encounters because I grew tired of that, I knew it wasn't going to make anything better. I didn't feel like going to parties because I burned out after doing so much of it (especially in France where I was half-drunk every morning). In short, I was bored with life and I hated it. Even if I met new friends, got to reacquaint myself with old ones, celebrate family events, I couldn't be happy, even when I graduated from college with double degrees. I wanted to be happy, but never could. So, I carried on with life, never enjoying anything and if I did, well, it never lasted long.
You know what got me over her and out of depression? Frankly getting her out of my life. We were still friends up until just over a year ago. I never told her the full extent of what I had gone through (I saved it until the time was right) and even if I wanted her as a friend still, friendship wasn't meant to be. I got on with my life. I concentrated on career, got promoted a few times, and better yet, I'm living the lifelong dream of running my own business, with my best friend, no less. I can't recall any time in my life than now where I've been this happy. I haven't started up dating again after so many years, but that'll be for another day.
However, I wouldn't advise that path I had taken for anyone, but it works for some people while there are thousands of worthwhile solutions to get over such a setback. Quite simply: just keep doing what you do. Work, get into a lot of activities, but also give yourself some time to put things into perspective. Some people feel like they have to forget thinking about the girl and relationship, and to me, that just doesn't seem healthy. Accept everything, take some time to breathe, and move on, but like I said, always keep things in perspective. You'll be alright.