I also agree with YellowAfterlife. You should look up version control (especially something like git). Then you should delete all code, really all resources, you don't use. Once I started doing this, my code and projects were so much easier to work with. You don't have to worry about losing code, because everything you write is saved, and you don't have to worry about auto fill, scrolling through lists of pointless resources, having finds turn up code you don't care about and having to figure out if it also needs to be changed, and so on.
That said, for a long time I didn't use version control. While for all the reasons above, this was a bad thing which I ultimately stopped doing, my solution at the time was that I would have an old/saved [resource] folder for each type of resource and if I wasn't using that script, object, font, sprite, etc. I would move it to that folder and change the name of the resource so that it started with old_ (old_scr..., old_obj..., etc.).
Again, this is a bad long term idea but if for some reason you can't learn to do version control right now, the above worked alright for me for awhile.
