I say: deal with the break-up on your own terms, at your own pace, in your own way.
If you have a support network of family/friends/mentors/& al. don’t be afraid to hit them up for support, that’s what friends are for; if you need someone to talk to, I’m glad to help if I can, and I’m sure other folks here are too, so don’t hesitate to ask.
Don’t feel pressured to react in any particular way (the suggestions to “find someone else” or whatever else right away are misguided; if picking someone up at a bar, or going on a bunch of blind dates, or flirting with every girl you meet will make you feel better, go for it, but definitely don’t do those things for someone else’s sake; do the things you want/like to do, not what anyone else tells you).
A long relationship can take a damn long time to get over – for me it took about a year, but now 7 years later it doesn’t ever even cross my mind.
A couple things I do recommend though: (1) to the extent you can, try to keep exercising enough, sleeping enough, getting enough sunshine, and eating healthy, and (2) make sure you get enough real face-to-face conversation in, and not just at work (and finally (3) I’d also really recommend trying to keep a balanced work schedule if you can – I know a couple guys who went through bad breakups and then dove 100% into their work and burned out hard).
Going from spending time with someone all the time to being single can be a big shock and throw off all your routines, and it can be easy to forget the basics. (In my case, there were a few months that were really bad, and I wish I had done a better job of just keeping up with the basic necessities of life.)
