It's common to try to work extra hours, stay away from home, or avoid being alone to prevent having to emotionally face the absence of a partner.
However, you'll gain a better understanding of what's happened if you spend some moments identifying the events that led to the break-up.
This step may be tough for you to do. If so, limit the time you'll allow yourself to think about the relevant facts of the situation to a half-hour a day.
Evaluate your relationship patterns.
If this is an isolated event, you may be able to leave it at that. Maybe your partner had a disturbing event take place in their life or perhaps they were on the rebound from a previous romance. If these types of breakups keep happening to you, ask yourself why.