Ahhh! Thank you for clarifying it was under the ways to login section. Yes, that's why you're unable to create a new account with that email.
As long as you still have access to your secondary email, you will still have access to your account without any problem. Actually, even if you don't have access to the email originally registered, as long as you know the password, you can still sign in (I tested this).
However, would you still like to remove your former email and make the primary email the one at your new institution? Is the email that you'd like to keep the one that is connected to your Instructure Community account (from St. Francis), or is that the one you'd like the removed and you'd like the other one to be the primary email?
Let us know!
Noah