I don't know what to tell you. I am not sure you are a hoarder...maybe. But I'm leaning toward frugal from your descriptions. Frugal is a step below full blown hoarding. haha. For example, a frugal person might keep a collection of screws in a kitchen drawer and maybe a small stash of old cool whip bowls to use when painting, but a hoarder will have 18 cans of screws and not be able to find them because they are scattered about and buried under piles of other stuff.
I'm going with what several people have said and am leaning heavily toward the INFPs by this time and the ISF/TJs. I, being a INFJ my ownself, am not saying one of our kind "couldn't" be a hoarder. I'm just saying that I would have trouble seeing it coming, but maybe that's because I'm clutter-phobic. Too much "stuff" makes me feel trapped and I have to get rid of things. I "keep" things and take "care of them" when they have a significant value in my life, but other things are just things and they can go as easily as they come