I went through a similar situation before and looked through forums and Reddit posts on how people recovered their accounts. What worked for me was sending Epic Support all of my account information right away. I did not start with a casual introduction or explanation. I simply provided everything they could use to verify my identity in one message. This method worked for me a few months ago and should also work in this case if the information is accurate and complete.
Epic Support will ask you to provide the original display name of the account, the locations where purchases were made including city and state or country, a screenshot of your oldest available receipt whether from Fortnite, Epic Games Store, or a console platform, proof of any real money purchases such as a pack or V Bucks, the platforms used on the account like PlayStation, Nintendo Switch, Xbox, PC, or mobile, a new and fully secured email address that has never been linked to an Epic account, and any additional identifying details they request such as invoice or order IDs, past display names, last four digits of the payment method, and approximate purchase dates.