I don't know that I am an expert, but here are some suggestions based on my experience.
1) Drinking does not help - it makes it worse.
2) I know people say you need to move on to someone new, which is true to some extent, but I didn't want to talk to other girls for quite some time after my debacle. I wasn't ready and it wouldn't have been good for myself or the new prospects. Only you will know when you are ready to get out there again.
3) Run. As much as you're able. This was a huge outlet for me emotionally.
4) The proliferation of social media has made moving on much more difficult in my opinion. You really need to block/ignore/unfollow any connections you have with the ex, and avoid social situations where you might bump into each other if possible.
5) Spend a lot of time with your friends and find other things in your life that you enjoy. Just try to remove yourself from dating-type of activities for awhile and focus on living life independently.