How to let go of collections?

I used to have more than 80 eyeshadow palettes, and I gradually got rid of some until I reached my current number of 68 (it should be less, but I bought new ones, unfortunately). Nowadays I’m much more aware of what I actually use and don’t use, but I have a serious problem with collecting. I have 18 palettes from the same line of a local brand, 15 from Beauty Glazed, and all the Naked palettes from UD. I know I could get rid of several of them, but the idea of having an incomplete line really bothers me. I also used to have all the shades of the same blush; recently I gave one shade to a friend and realized I felt fine about it, but I feel like my tendency to collect is stronger when it comes to eyeshadow palettes.

*English is not my first language, please let me know if anything is confusing