If you were happy before you knew someone, you can be happy when they're gone. 

You can't be happy if you're still holding onto people that have already moved on. 

Keeping baggage from the past will leave no room for happiness in the future. 

Cry as much as you want to, but just make sure when you're finished, you never cry for the same reason again. 

Know your worth. Know when you have had enough. And move on from the people or situation that preventing your happiness.