won't open on steam

I bought stander vallew on steam 2 months ago and i was playing normaly, but yesterday the game didn´t open. I tried everything that i found on internet but nothing worked, including open the exe without the steam launcher, reinstall the game (in the same local and in a HD), downloading and...

I play mod games I launch from a separate file but on my main Steam game, I log into to Steam, launch my SDV and it opens to then immediately drift down screen and not be able to keep on my monitor even from the bottom icon! It started yesterday and today it is still the same!! WHAT DO I NEED...