During my life I've collected many different things for many reasons.
Mostly because I like them.

Its possible you do not have a shoe fetish, just that you like shoes and collect them.

If you are compelled to buy and collect shoes for a sexual purpose you might have a fetish or you might be lonely and identify shoes as a way to find someone so you are no longer lonely.

If you get turned on (or off) by shoes then you likely have a fetish.
If you must buy shoes you might have a compulsion.
If you dream and fantasize about shoes that yearning could be an indication of a fetish and a compulsion.

If you obsess about shoes and it disrupts your life or the lives of those you care for you might have OCD. In which the "D" stands for disorder.

Most everyone has obsessions and compulsions but they are not OCD if those obessions and compulsions don't disrupt their lives.

If you have a large collection of shoes you might want to have them appraised. Ya never know, someone might pay you buckets of cash for a pair to add to their own collection.

If you lay in a pile of shoes and masturbate, yup, its a fetish.