decrease visitor & google don't index my content???

hi
visitor of my site was 900 ip in day,en masse visitor of my site decrease to 100 ip in day and alexa of my site from 9.000 increate to 60.000.
and my post is not in google index when i search them.
i use yoast for sending post or page in wordpress but i don’t kwon how i solve this problem.

Is it possible that someone has hacked my site?
my site is : archi-arch.com

please help me 🙁