My source is me. Same as with you. End of story.
My source is external to me. You are mistaken. If you ask me the source of my morality, I've told you where it comes from, and it's not me. Now, you may claim that the source is in my imagination, and that's fine. But it's a much different claim to say that my source of morality is external and objective, thus I have the philosophical foundation to say that something is either moral or immoral than it is to say that the very concept of objective morality doesn't exist, yet you are "morally corrupt" and should be embarrassed for disagreeing with me. (As you have done here.)
Similarly, it is a far different claim that humans are made in the image of God and so are a different class of creation with inherent human value and dignity than it is to say that human value and dignity are products of my personal imagination, so it's morally corrupt to own slaves.
Again, you may claim that my source for human value and dignity is in my own imagination, but they are two far different claims with two far different metaphysical repercussions.
Worldview tests are there to explain what we experience as reality. You and I both intuitively perceive and live as though an objective moral standard exists. You've been incapable of treating m,e as though your morality isn't objective. I've pointed it out. In action, we agree that morality is objective.
Yet it's my worldview that explains this without having to explain it away.
You and I agree that humanity has intrinsic value and worth outside of your imagination. But you have to deny that while living as though you believe it. My worldview can explain that and yours has to explain it away.
So, if you and I both looked at a mathematical answer, came to the conclusion that 2+2=4, and yet I was the only one that affirmed that math exists outside of your imagination, it would be an obviously different claim for you to point out that math is only in our imagination and my belief in math is only in my imagination. Whether you think math is only your imagination, it doesn't change the formula. If you believe that my belief in math is only in my imagination, it doesn't affect the existence of math or its affect on the formula.
At the end of the day, feel free to deny the source I reference. It's between you and God. But stop with the silly equivalency pursuits between your claims and mine. Mine answers questions that yours can't, which shows the philosophical differences between them.