Well since the only topic you have started is this one, I figure you are really talking about a post and not a topic (unless it has already been trashed by a moderator, but I did not see it in the modlog).
If it is post, and you cannot delete it, you can always edit the content a place a more suitable one. If it is a topic you are on about, you can move it to another section such as off-topic archival, lock it, and let it wither away there.

P.D. You may want to review some of those "great concept" or similar posts you have in your history, and consider creating better content …