I highly encourage you to join your high school football team this season. It will still not (yet) be too late for you to start playing football again.
Based on your height and weight, as well as the fact that you play golf, I believe that the best fit for you is at quarterback. You have the ideal size for a high school senior quarterback.
My best advice for you is to work hard and perform very well in practice every day. In addition, what you need to do this autumn is eat healthy, exercise by doing weight lifting, and either jogging or going for a long run every day. If you do these things, you will get faster, stronger, and into better shape, which will greatly improve your chances of being a successful, top notch quarterback in high school football this season, who could go on to play college football.
By the way, your chances of getting a scholarship to play college football depend on your performance in football during your senior year of high school. If you perform very well in football this season, you will greatly improve your chances of getting a scholarship to play college football next season.