Create a Main event sheet.
Now include an eventsheet called variables (make it and put all your variables there)
Now include a eventsheet called functions (make it and put all your functions in there)
Now include a eventsheet called changelog (make it and put all you changes via comments in there) etc etc.
you can make groups that have eventsheets included.
The purpose is to have a main eventsheet that pulls in code from everywhere else.
One new eventsheets you can then include main eventsheet or something like that.