Turned out it was just a dead end inserted in the code as a trick to "eat" out time out.. My teacher gave me a tip into trying not to get in that area of the code and I was able to solve it after that

Yes, that's right.. I was able to derive my key using your tip. Thanks!

Yes, @joshpoley, that's what I also found.. And then division crashes my program. I'm not sure yet if I'm on the right path. I asked my teacher for some guidance and he told me to look more into error handling and debugger evasion techniques which I found an example here: autosectools.com/Anti-Debugging-With-Exceptions.pdf