Problem with an iCloud+ and running out of storage on the device

I’m reaching out for help here because I can’t find a solution to my problem anywhere. I have an iPhone 14, and this is my first Apple phone. I’m running out of storage on the device; I have 128 GB. Most of it is taken up by 6,000 photos and 900 videos, which are using up 83 GB—is that even possible? Additionally, many apps, like WhatsApp, which took up around 500 MB in the morning, are using 9 GB by the afternoon. I have an iCloud+ 200 GB plan, and my backup takes up 89 GB, even though I read it should only take around 2 GB. The photo library uses the majority of that—79 GB. My photos won’t sync to iCloud due to a lack of storage. Has anyone experienced something similar or know what I’m doing wrong or what settings I should enable? Thank you in advance for your help.