Gutenberg is coming. Gutenberg is included in WordPress 5 which is slated for release on 6th December 2018. This is avoidable in the short term, by preventing WordPress upgrading or by upgrading and then installing the Classic Editor plugin, but this plugin has been announced as only supported until 31stDecember 2021. After this the Classic Editor will no longer be supported.
At this point you either need to switch to Gutenberg or find an alternative to WordPress.
That alternative might be another CMS, another blogging platform, or a WordPress fork.
I mention that last as a new WordPress fork called ClassicPress has been announced which I've been looking into and I think it has possibilities. I'll have more posts soon on ClassicPress as I continue my investigation.