If you haven't already, submit your website to webmaster tools.
Secondly, have you checked if your website has any manual penalties?
![](https://i.gyazo.com/6915e50d190a59916d059ee0d724bb6d.png)
That looks like link building to me. Link building always carries a risk of a penalty.
Another thing I found, which I don't think will be the reason... but a major quality signal...
You have a tiny website, yet half the pages you link to internally redirect, I'd sort that pronto.