How can I learn to find myself and mature?

I really want to learn to control myself and be strong.. there is a lot of pain in my heart that I know is only there because i brought it upon myself. How can I learn to think more positively and be more true to myself? I really want to mature and be able to face the harsh reality of this world, but also become happy with myself and my decisions.. i feel like its in me but I just can't get it out. It just keeps hurting me.