How do I relief stress an anxiety. how can I stop scattering thinking. Its hard.?

Im always stress,and frustrated, and always worrying. My thinking just wonders an scatters of different thiings. I want to stop. Im 22 and female. I want to be stress free. I also have anxiety. I want to get rid of it. So I can feel healthy. My chest tights up all the time, and the left side of my chest hurts sometimes. I want to relieve this fast. What should I do, how.can I overcome this stress and being worrief. All I do is think about alot of stuff. I need help, what should I do, I feel overwhelmed alot. I wanna clear my mind, relieve my chest pain an tightnes, an get rid of this stress/anxietys. What can I do? What are somethings to help? I also take vitamin B complex (stress), just started taking them.