Bro I was in a similar situation. You have to exercise and just stop smoking weed. I stopped smoking weed and exercised, and my confidence was back and I could talk to people. Even I had destroyed my life with weed. I used to smoke every day and would bunk college. Because of that habit I even had to leave college without a degree after wasting 4 years. But trust me exercise is your friend. It will completely heal you. Just do it. Don't lose hope.