IIRC ageplay is commonly recognised, and there are sites like Guardian Island that cater to it.

Psychologists used to, and some still do, use age regression as a form of psychotherapy, so being aware that at times you're not feeling your physical age is certainly nothing to worry about.

In my limited experience it's best to allow yourself to go with it in a safe environment, as personally I find when I'm feeling "little" I'm alot more emotionally fragile than I are when I'm emotionally feeling more my physical age.

There is however a frustrating lack of proper psychological research in this whole area that I've personally managed to find available on the net.

Just allow yourself the space and freedom to feel however you wish to feel without judging yourself for it, and surround yourself with people who will indulge you and look out for you as much as possible. I'd certainly recommend where possible speaking to a professional about it though in order for them to help you work through any deep rooted issues that could be underlying this and triggering it to occur.