For now, if you're a long time user and need to find your history, here's a trick: In Chrome, hit `F12` to open "Chrome Developer Tools", then choose the little magnifying glass on the bottom. Then go to your profile image being displayed in the page, and it will show you the file name of that image.
Once you know the unique file name of your avatar, go to Google and search for: "my_avatar_name.jpg site:oxwall.org". Google indexes source code of pages, so you can find all pages with your avatars!
TL;DR: Search for the file name of your avatar image on Google (with results narrowed down to oxwall.org) to find your post history.