Thumbelina is not about shrinking though. Alice in the Wonderland is and Gulliver's Travels, too, but not Thumbelina. I do not have this fetish, or any fetish for that matter, but I happen to very much relate to that scene in Alice in the Wonderland in which she is too big for the door to the garden. She sees the light coming from underneat the door and through the keyhole, but cannot make herself shrink, at that time, to enter the garden. Metaphorically, it describes a lot in my life, although not related to physical size at all, but simply because I did not realize that I had the right key for the door leading to the garden, or, did not dare to use the key. So I can relate to that part - if you want to shrink to enter that garden, then sure I can relate.

Thumbelina (no shrinking but yes miniature size) has a happy end, so living in that kind of fantasy should not be painful. Alice in the Wonderland has quite a happy end, too. So you seem to have an optimistic fetish in the end.