Staying in a Hostel?
Department is next to Hostel?
Great than greater!!!
You don't need go anywhere. Open your laptop, write lines of codes till you tired and then sleep in any position. After all this is hostel. So complete free and no interference from family. Occasional booze with friends with alright. When bored open laptop and play chess. Or Facebook is there blessed by Android.
Good, you are in college, you passed teen years and have 12 year certificate to show your success. All above things are good, pretty good, shows a sign of adulthood. But as you know nothing is permanent so not your adulthood.
Sports is not equivalent to Candy Crush and online games. I am not against computer games but your body muscles too need some care.
There is an old saying, healthy mind lives in healthy body.
No matter whether your studies need outdoor work or not but your body need outdoor activities. Get up, go to Gym.