How to regain control and purpose in life?

I have absolutely no idea what I want and seek from life. I do this, I do that, but overall nothing seems to satisfy me. Sometimes I go party and dive into a "cheery" mood, but I don't find any satisfaction in it. Then I go being an introvert. Not that I want to be an introvert. I just don't know what I want. For a brief time I got interested in maths or physics, but then I lost interest in them. Lately I'm feeling so empty inside. It's like I have no soul or something. Nothing drives me to forward. Life is becoming a living hell for me.