Problems with email on iOS 13.1.3

Hi - on my Ipad with the new update to iOS 13.1.3 I’ve had all kinds of ‘gliches’ with email. My sent items automatically double in the sent outbox. When I try to open an attachment or even a new window on a received email, the window opens up only to a quarter of the size of the screen and will not enlarge. When trying to compose a reply to an email - the original sent email does not display on the screen, so there’s no way to view it, other than to exit and look in the received. If this can’t be rectified, how do you reload the last iOS version so the email would work. Thanks for any help!