Google Not indexing site at all

Basically I have a niche site that is based on different categories and kind of a very rare niche. It has good DA/PA:

http://prntscr.com/plg3n7

Issue is that google is not indexing the site at all, it has stopped indexing and is not indexing the new articles. It has been like a week, is my site in sandbox mode or what?

Have you submitted a sitemap to Google Webmasters? This can really help speed up the indexing process as you are explicitly telling Google you want your site indexed, rather than waiting for their spiders to discover your site.

Check search console for the domain. Any issues will be reported to you there.