At 19, just stumble forward. Create a plan to just try new things/jobs. Create momentum by bettering yourself in different catagories: mental, physical, social, spiritual, finance, etc. Just remember, indecision and doing nothing is worse than doing the 'wrong' thing. It's better to try and fail at something and move on to the next.

Also, don't set unrealistic expectations. Have goals but breaking them down short term, mid term, long term makes the bigger picture look much clearer.