Consider getting professional help. There is no one best way to cope with the breakup of a relationship. Each of us is different. Some people find that it helps to lose themselves in the company of friends. Some don't want to be around people.
Some people find it helps to get away to an entirely different set of conditions.
Some immediately try to look for a new love interest. Most who try this find that until they get over a previous love, a new relationship is impossible. Nevertheless, there are some important guidelines for coping. First, don't try to immediately repress the hurt. So the first step is to accept your hurt as normal and expected.