As you are not able to reset your Instagram password using your email address, you can use your Facebook account to reset the password. To do this, you can follow the steps below:
: This option can help you only if you have already linked your Instagram account to your Facebook account.
1. On your Instagram login screen, click "Forgot your password?".
2. Go to "Username or Email" and enter your username or the email address you used to create your account.
3. In the top-right corner, tap "Search".
4. Go to "Reset using Facebook".
5. You will be prompted to login to your Facebook account (if you are not logged in already). Once you have logged in, Instagram will bring up the account most recently linked to your Facebook account and will give you the option of creating a new password.
6. Follow on-screen instructions to reset your password.
The following link can be useful: