Work upstairs and downstairs:
Change your study space by working at your dining table in the morning and your bedroom desk in the afternoon.
Use a timer:
Work for a solid 30 or 45 mins before getting up and changing your scene (can be as simple as getting a glass of water or just climbing the stairs).
Doing something is better than nothing:
Even if you’re feeling really unmotivated, just read through your notes or just complete half a lecture. Over the days, you can gradually increase this until you get yourself back into a good rhythm.
Turn off your phone:
It’s so tempting to start scrolling / texting, so just switch it off completely and keep it out of your room, until your lunch / dinner breaks.
Plan an afternoon activity so you can fully relax in this time. It gives you something to work for / look forward to and can also perk you up for any evening work.