For people of your age sleep should not be a problem, you are anxious and nervous.cool down do some physical exercises, yoga or breathing exercises which will reduce your tensions and worries.

You seem to be having a lack of physical activity. 1 hour of brisk walking towards late evening will go a long way in helping you. Set alarms to ensure that you don't sleep beyond 8 hours at a time. A full dinner, a bit closer to bed time also helps a lot. Install blue light filter so that your phone doesn't mess up your sleep and put your phone away 1 hour before bedtime. Start dimming lights an hour before bedtime.