In what you wrote there is not a single specific thing that I could refer to. Your argument is this: my thought experiment must be carried out incorrectly, because the special theory of relativity must be true. This is gibberish.First, I think some of the negative comments are unwarrented. SR can be a real problem. Especially in this kind of case.
I, too, caught a similarity between your paradox and the twin paradox. Both explanations boil down to the same difficulty.
It's really nice that so many things in Physics can be explained by diagrams and simple logic. In this instance we can't do it. An expert might be able to prove this to you but unfortunately I'm not one. All I can do is point out where your logic is wrong: You are trying to understand the problem in terms of Euclidean Mathematics. Unfortunately your paradox and the twin paradox share a similar feature which is very hard to picture and understand until you can handle the advanced Math. Both paradoxes expose that SR uses what is called an "indefinite metric." This is the SR version of the "dot product" between two vectors that you may be familiar with. That means when we "square" two vectors in SR the result can actually be a negative number. It sounds ridiculuous but it's true and is the source of much confusion. (This is the meaning behind my previous comment: You can't separate the space and time in space-time.) Like I said, I can't draw the pictures to show you how to do it. My apologies for that. But the experimental successes of SR show that the Math is correct.