Without knowing the history of your family dynamics or anything about your parents’ relationship, I honestly think it might sound and feel worse than it is under the intense circumstances that most everyone can relate to in one way or another.
I think talking to your dad (nicely, not accusatory) about how you feel and that it scares you that he even potentially would consider exposing you or your mom etc. to this virus makes stresses you out and that the fight he had with your mom upset you. See how that conversation goes and suggest maybe just a little note from him to her expressing that it was a regrettable situation that tempers should not have got so heated.
It doesn’t have to be “I’m so sorry etc.” bit rather just acknowledgment that it’s all gonna be ok and work out. A little sincere comfort lasts longer than a lot of cold shoulders. Talk to your dad.