First of all heartbreak is real and there is no way you can escape it. In fact the healthiest way is not to escape it. The first step should be "accepting what happened" and acknowleding your loss. Yes, it is really hard, extremely painful but it has happened. Seeing things with a realistic attitude will help you ground your feelings although it can be hard at first.
One of the most important things to get over a heartbreak is forgiving. Maybe you have said the wrong thing, maybe your friendship or romantic relationship has ended because of you, just forgive yourself. You have made a mistake, you had your own feelings and reasons at that moment so it happened.
Forgive yourself and the other person and be grateful for everything you have shared together. In order to get over heartbreak people tend to spend time with others. Although it is quiet important to have an emotional support system make sure to not get burn out.
Instead of over socialising turn to yourself. Start to care for yourself, focus on what you want. Asking yourself "What do I need?" is such an important thing to do. Try to understand your feelings and accept it. Remind yourself it will pass and your mistakes have helped you be a better person for your next relationships.