I have a website with an integrated Web service (an app for card divination online). Age of domain is already almost 2 years. Naturally, I wanted to make my site popular. First I submit my app in the link directory. And the effect was good. But then I mistakenly ordered the services from one 'SEO expert'. He just spammed my site for blogs, forums, etc. As a result, now the site has only 20-30 visitors per day. It is very little for a unique resource. Perhaps Google specifically lowers the SERPs for my site. How is it possible to check and how to get rid of this?