Unusually Large iCloud Backup Size iOS 10

Hi, I have an iPhone 7 with iOS version 10.3.1 installed. Strangely, my phone refuses to backup to iCloud. I've had the device since launch and have never had this problem before.

I only have 8 apps and 105 photos. The iCloud photo library only takes up 377 MB and the iPhone backup itself only takes up 2.6GB. I have 2.2 GB available of the 5 given to me. For some odd reason, the next backup size is 6.58 GB. I've never had this happen to me before. When I try to backup the device I receive the error "This iPhone cannot be backed up because there is not enough iCloud storage available."

I've tried some simple things like turning the phone off and on, and turning the iCloud drive off and on but no luck.

Thanks.