I used to love a girl. It was single sided, It was back 6 years ago, I fell in love for the first time. Her memory still hurts me like a hell. Help me?

Find a local source. It sounds like you are stuck and preoccupied with one relationship. You can' t fix this on the net.You need to find an unrelated counselor/adviser to help you learn how to move past the issue and continue in life. It will take time, likely months or years, but cannot happen unless you commit to doing this.