Literal Inability to do Work Sooner than the Night Before it's Due

[dethgrind]

Pack a bag with only the absolute essentials you'll need to get your work done, plus a snack if it's going to take a long time. Walk a minimum of 15 minutes to a library or coffee shop where you won't have tv or internet. Turn off your phone. Set a specific time that you cannot leave before, eg "I will stay at the library until 7pm".

Hardcode into your weekly schedule times that you will do this. Treat it like work or a class, ie you will not skip this. If you post your schedule on your wall for your roommates or whatever, write this time block in there. If you don't have any assignments due, catch up on your reading or review your notes.

Oh, missed the part that you were in HS. This advice is obviously for college but a lot of it will work for you too. The idea is to physically move yourself to a distraction-free environment and make it inconvenient to leave. You might also try telling your parents, siblings, friends, etc about your big assignments so that they will hassle you to get your work done. That's often just the impetus I need to get up and leave the apartment to work.