If you find yourself being unproductive, then just...don't be.
Get a job. Go volunteer. Become a lifeguard, a lab tech, look for an internship, STUDY.
If you aren't doing well in school but do nothing except play video games, then you do not need advice. You know exactly what to do. I can tell you that things will be very different in college. They really don't care if you don't do well. They'll take your tuition, but they'll kick you out if you aren't making the cut, regardless of the reason.
Becoming a doctor is difficult, it takes lots of work. If you want to become one then you need to start earning it. Thankfully you're in a position that you have not shot yourself in the foot quite just yet. But it's real and happens all the time. Feel free to go through the threads of people who underperformed in undergraduate school, and are now doing post-baccs and Masters programs for another $50K- $100K AFTER undergrad just so they can GET IN to predoctoral programs and take on THAT tuition.
Put down the remote and get used to being in your books, because if you're lucky that's where your nose will be for a long time.