I understand they are upset about it but where in the conversation did he say he'd disown you or your family did? Your title implies some very strong statements but I don't think I'd equate calling you selfish with disowning you.

That being said you need to do what you need to do to be independent. If you can support yourself and move out, I would agree it's time to do so. Is there any reason that you can't other than your family opposing it?