The other members above are complaining that they cannot publish posts. You seem to be complaining about a different issue: that your posts don't show up in the WP Topics pages. Am I right?
To turn all your latest posts to drafts and back to published, you'd go to Posts > All Posts, click the "Title" rectangle to select all the posts on that screen, select Edit from the Bulk Actions pulldown, click Apply, select Draft from the Status pulldown, click Update, then select Published from the same pulldown and click Update again.
But you have no reason to do that: if you had HTML errors, the result would be a messed-up blog front (sidebar at the bottom, or posts in the sidebar - that sort of thing). Selecting the auto-correct option then turning your posts to drafts and back to published would correct such a messed-up appearance: it has nothing to do with either the inability to publish posts or the disappearance of your posts from Topics.