In general, such threads are generally found in
Forum and Community Questions
I believe mods can delete accounts, but prefer not to do so. The best way to 'delete' your account is to delete all your posts and change your username, if it's anonymity you're looking for. If it's more a case of wanting to make the account inaccessible to you, then you can change your password to random letters (typed without looking), so that you can't access it any more.
I wish you all the best and will be sorry to see you go!