Doubling down to justify an earlier bet

A position already taken is not evidence about the price now. Adding to it because it has moved against you is the sunk-cost error with odds attached.

A line moving against your position is the market telling you it disagreed and got more confident. Reading that as improved value requires the market to be wrong, and requires you to be more certain of that than you were before.

Sometimes it genuinely is wrong, and adding at a better number is correct. The question is whether you would open the position at the new price without holding the old one.

Which is where it goes wrong. Holding the losing side is the least reliable moment anybody ever has to assess whether a market is mistaken, and it is exactly when the decision presents itself.

What to do with it. Ask whether you would take this bet cold, with no existing position. If not, the existing position is doing the arguing.