If you've just ended a relationship with your partner and sitting there feeling your heart was ripped out of your chest, then no amount of empathy from other people will get you to feel good. Breaking up is like losing a limb. A part of you was taken away.
It's not easy to be happy when your heart is broken in pieces. People around you who care may try consoling you. They may say that you'll get over it but it's really not that easy.
What you should do is to slowly get your mind of the break up. Try to bring back your self-confidence and slowly focus on things you love. It will not be easy but for the mean time you need to survive.
Take comfort in the thought that thousands of people all over the world are breaking up right now. You are not unique; thousands are feeling the pain of separation too.
Let me get you in on a small secret, 90% of break ups can be reversed if you know what to do, so for the meantime just heal yourself. When you are strong enough, think if you still want to get your ex back.
If you've decided to get your ex back then listen carefully.
Plan it as soon as possible, your ex is not going to be around forever...They will eventually find somebody else and they are going to hook up with them...They are going to fall in love, they are going to have sex...so on and so forth...