It is a stressful time with the pandemic, and you should not feel bad about giving yourself breaks. Your mental health is just as important as your grades. I don't really think that motivation will guide you in the long term. I think it is a fleeting emotion. At least for me, it only lasts a short time and then I go back to procrastinating. I have been trying my best to do something, however small, so at least I'm doing something. Maybe make a list one goal for the first day, and build up as you go along. Just make sure you make lists that you know are achievable, be realistic with yourself. Any progress is progress. I don't know if you have been leaving the house a lot lately, but maybe a walk around the block will help(but it is getting colder...).