Your dad is still your dad, not David. You don’t have to start referring to him as your uncle because you are his kid. He raised you and loves you and DNA doesn’t change that. Your mom and uncle committed a pretty big betrayal but that’s on them. Yes, you now have to deal with the aftermath but all of this happened before you were even born. All your memories are still real, your experiences, and the love your parents showed you. The ONLY difference is the percentage of your DNA that you share with the members in your family. Not even the DNA, just the small amount. Your dad is still your dad and your uncle is still your uncle and all the issues that will happen will be about the betrayal, not small percentages.