Missing email folders in Mail app after deleting and reinstalling Mail app

I spoke with a Comcast technical support person on the phone yesterday because the mail app on my Apple devices was getting error messages, including, “Authentication failed,” and “Alert.”  The tech told me to delete my email account and then reinstall it. I followed those instructions, but now all of the folders I had set up in my Mail app are missing. I still see them on Comcast webmail, but they no longer exist on my iPad. I’m afraid to delete the Mail app on my iPhone because I assume I will also lose all the folders there.

Is there any way to find the folders or do I need to laboriously go to the Comcast webmail, then use that as a model to re-create all of the folders, I had set up and try to find all those emails that had been nicely organized in the folders?

thank you in advance for your help