My subpages disappeared from G and rank dropped

Hi guys,
I created really good MNS few weeks ago.
I was ranked 2 and 3 but yesterday all my subpages are gone from Google but they are indexed.
I didnt do any backliking since i was 2nd for some weeks.
Also my homepage dropped from 2 to 3rd .
May I be victim of negative seo? Any suggestions please?
Thanks

That's penguin, not negative seo.