If you have a variable that strangely gets destroyed, and you have a block of code that affects that variable, my question has to be: Did you really read the code?

When searching for an error, it isn't enough to just read code lines that mentions the name of a variable. You also have to look for other source lines that may modify a variable, i.e. all lines containing pointers or making indexed array accesses.

It is important to learn to read code, and to learn what to look for. Asking for help on a forum will not give you any training in finding your bugs. You must spend own time, and you must spend that time in a rational way.