improving functionality of lengthy macro

Good day,

I am looking for some simple advice,

I did my undergrad in computer science however we always worked with simple programs (about 100 - 200 lines of code tops)

For work I am making an excel macro that seems to get larger every day and I am starting to get lost in my won code ...

or at least it takes me a while to find the place I'm looking for ....

what is the best way to organize my code?

I try using comments for every few batches of code, however I am getting close to 1000 lines of code,

I would think dividing my code into sub functions and calling them would be better,

any other suggestions?