SP2013 - library settings won't let me edit certain columns

I have FULL CONTROL perms on a library that I’m working on. However, when I go to the settings, some of the columns won’t let me click on them to make changes or delete them.

Here are some of things worth noting:

• When I open the library in SPD and click on EDIT COLUMNS, I can only see the columns that I’m able to click on in the site; The other columns don’t even show up here.

• The columns seem to be single or multi line TEXT fields.

What do I need to do in order to change this?