1. Make a to-do list
List the things you want to finish and follow the list. Prioritise the most important and urgent ones. Cross them out immediately when you finish them.
2. Relax yourself in your own ways
Recharge yourself. Watch a film, have a walk, listen to music or have a nap. I personally find taking a shower very useful when I am out of motivation.
3. Avoid procrastination
Clearly, procrastination makes the situation worse, because you will end up with a lot of work going to do in a short period of time (usually when you can't procrastinate anymore). Similar to tip 1, try to make a list of the things you have to do. Meanwhile, find out why you were procrastinating. If it was because the work was huge in terms of workload, distribute it evenly and sensibly. If the work is boring or unpleasant, try to have some pudding or fruit (or whatever you like) while you are doing it to make it more pleasant.
Moreover, it is very important to clear up your working area and get yourself into the mood of doing work. If you can't stop looking at phones during the work just like me, set a time limit or app limit on your phone to warn yourself. I like to put my phone to somewhere I can't see or touch, for example, under my bedsheet.
4. Find a listener
It might be your friend, your family or your diary. Tell them (write down) your progress.
5. Breathe
Breathe! Get some fresh air by going for a walk or simply breathing. Don't feel like a rock is stuck at your chest.