We all had done mistakes or hurt people's feelings. You might regret it for sometime and for sure you wanted to ask for their forgiveness. Some of us can't really mention the "sorry" word, some will just let it go with unspoken words , some offer a peace offering to make up with their mistakes. Ask for the forgiveness no matter how hard it is.
We have different level of mistakes, and sometimes it can pierce through your heart and will leave wound that is hard to heal. And some says that time can heal wounds. You might say that is hard, well, it is. What can you do about this? Give yourself some time, focus on yourself, LOVE YOURSELF. And do yourself a favor, don't burden yourself with those unpleasant memories, don't imprison yourself from the pain, seek God. Put it all behind you. Remove all those hate that's eating you up. It will not help you grow if you keep holding into it. Trust the process and in time, you'll learn how to Forgive the people who have done you wrong.
Forgiving people can lighten your heart and it'll make you happy. You'll find Happiness if you unburden yourself. So, find it in your heart to always forgive. Remember, you're doing it for yourself.