Selfish how? Are they counting on you for income and financial support? And if you should get Covid and die will they be left destitute?
Tell them if they want to see selfish, watch you write them out of your will. Now that would be selfish.
They should be cut out of any will.
When they call someone “selfish” they are trying to make you their slave.
You are saying they have no right to live except to satisfy their whims.
That is what an enemy looks like.
“You are selfish” is a declaration of total war.
No compromise is possible on this issue.