It’s not “my” fallacy, it’s A fallacy.
You’ve said your quitting, you’ve admitted you’re not happy and the only reason your staying s because of the time you’ve invested so far. BLAM Sunk Cost Fallacy. It doesn’t matter what you say, it doesn’t matter how hard you try to rationalize your decision, you’re a victim of this fallacy.
You’re going to put effort and time into something you’ve admitted you don’t like, only because you’ve already put time and effort into it.
If you don’t want to fall victim to the sunk cost fallacy you’ll quit now, but you won’t. You’ll also buy the next expansion.