Q: Can't Free Up Space, Macbook Pro- (Help Please!)

This is how much space my computer says it has. The total space really isn't much compared to other mac computers for some reason, but as you can see, it is almost full. The problem with this is that I don't even have a lot of files on my computer. Just a few apps, a few pictures. The application that takes up the most is only 2 gigs, as you can see below.

Most of them seem to barely take up any space at all!  And if i go into "all my files" inside the finder:

Everything under that is just around 1-10 mb or even 3kb. And see, I've deleted a ton of stuff. Ive transported thousands of photos out of my computer and into USB storages. But the space just won't change.

I do not use time machine, which I know is some kind of back up program and I used to have Garage Band which came with the computer, and downloaded an around 42 gig update, but when i deleted all garageband files the space did not free up at all. This is a really irritating problem because I would like to have space for things, but I don't even know what is taking all of it up and deleting things does not help.

I have tried the searching for large files thing with the "greater than 100 mb" trick but almost nothing but applications popped up and i only had like 10 results.

There is nothing in my iPhotos trash, and I currently only have 36 photos there.

All I really have in downloads is some silly pictures, and a few mc modpacks (like 4) which i have tried deleting some before but they did not free up space either.

I simply can't see what is causing this, I have searched everywhere online but no solution has popped up. Maybe I haven't searched hard enough, or maybe Im the only one that has space issues this bad.

So, I would like some help... please? Do any of you know how this space issue could be resolved? Im no technical expert, so this problem seems beyond me...