Why any my works are not exist in Stock? I can't find them anywhere.

Searching by keywords isn't enough. Adobe dosen't make it that easy. Like search engines in internet, Adobe has search  algorythms. This keeps contributers from forcing their items to the top. I think such things as image views, downloads and sales play a role on how an image is placed. Maybe even the upload date or the size of a contributors portfolio. Like I said, I don't know for sure but that is my impression of comparing my searches with the items keyword.

Your forum screen name turns up nothing on a search.  So I assume you're submitting under a different name.

Do you go to the end of the search list? Some keywords have millions of videos and you may be at the end of the list - so it could take many years if you for example are searching for a keyword "flower", which has 18 million images in competition with yours...