Migration of forum posts and blog comments from the old site

I was trying to find an old comment of mine, and My content page which used to be in the profile is missing, and there is no dedicated search form, so I can’t search my content by username.

If I click on my username in any recent blog comment, it does show some recent posts in an auto-expanding feed. However, it only says “36 posts”, which is far less than what I made through all those years. Also, older posts from 1-2 years ago are marked with bogus dates like “5y ago” or “15y ago”, and the actual text is full pf HTML code tags like <p> <br> <em> <blockquote> and even <span style= > <a href= > <img src=>.

Where are all the old forum posts, what went wrong the few posts that remained, and are there any chances of having this fixed?