I can't do anything on off days

I am a Master's student. Days when I am not at the university or have no studying to do at home, I don't know what to do with myself. I cannot seem to finish my errands, or do anything really. I just lie in bed, either crying, sleeping or doom scrolling. On the days I do have things to do at/for university, I am too tired to do anything at home. What is this? I just want to have enough energy to cook and clean man. But I never seem to do.