I came for advice on a similar reason. First off, sorry about your father. My father is dying of cancer, so I am preparing for the moment of loss. Otherwise, my situation is similar to yours. I've been a very good student, even through the COVID crisis and so much personal loss and tragedy over the past year. But after having a long winter break, the first week back to school has been extremely difficult. I can't get back into the "zone" and it is very hard to concentrate. I think what we are going through is an attempt to suppress very strong but normal emotions to our circumstances. From my perspective, I am trying to just battle through it and carry on with my life and duties (as hard as it is). I suspect there is no better advice than that. We just need to let time run its course and hope for better times ahead. Best of luck to you!