Is there a way to retrieve direct messages that I've deleted from my Twitter account? I have tried downloading my Twitter archive, but I'm having difficulty discerning whether the deleted messages exist there.
You cannot retrieve deleted messages in twitter.
You can check it at your email if you have linked your email unto your twitter account, then you should find it there. You just have to search in your email`s inbox.
Deleted DMs disappear from both the sender and the recipient`s history. If you are missing DMs, check with the person you messaged to verify that they deleted the DMs you are missing.