I speak for myself and a lot of other people when I say that we often dwell on mistakes, heartbreaks and sadness instead of trying to overcome it. However, you must understand that you are the only person who ultimately can make a certain situation better. So, here are some very cheesy but yet honest advice for anyone who is recovering from a broken heart and wants to be happy.
You are amazing.
You are capable.
You can overcome anything that is holding you back.
You are able to fight any obstacle that may stop you from achieving your goal.
Think positively.
Think well of others.
If someone is negative, don't spend time with him or her. It's simple, if you don't like the smell of garbage, don't be near garbage. Similarly, if you don't like negativity, then don't be around negativity.
Don't compare yourself to others. There are somewhere around 7.4 billion people in the world. We are all different and unique for a reason.
And lastly, you have people who care about you. Never be afraid to reach out when you need to. But remember, ultimately, you are the only one who can make your life better.