I did a factory reset and my Reminder items are gone. I always back up everything on iCloud. Help!
Did you do a restore from your old backup? Was iCloud back up turned on for reminders?
Yes and yes
Configure your device for use with iCloud, enable syncing of your reminders, and within seconds, your reminders should sync back to your device.
I already have that but they were lost when I did a factory reset.
I'm sorry, but I cannot understand how that happened. I've restored my devices more times than I can recall, and yet, my iCloud stuff is always intact. Did you have more than one email account configured? The reason I ask is because it is possible that your notes were synced to it instead of to iCloud. If you go to Settings - Notes - Default Account you will see which email account is set for your notes to be synced to. Therefore, if you had more than one email account configured prior to you resetting your device, login to that account online to see if your notes are there. While you're at it, login to iCloud.com and verify that your notes are gone.