Well here might be some reasons why.
A: It was moved to a different forum.
B: A mod deleted it
So with that being said if you can't find it within the first two pages of every forum, then it's gone. My theory is that it might've been deleted due to something that was against the rules or inapproaite. Therefore considering I don't see it in your history, your last recent post was on the 21st, so maybe you might want to contact a Moderator or Admin to see why you can't find it or what did you do wrong. Or as a second option you can post it again and see what happens.
Best of Luck :D