I have 2TB WHY IS MY PHONE SAYING MY STORAGE IS FULL

You bought iCloud storage, iCloud storage does not increase your phone's storage. iPhone storage is a fixed size and cannot be increased. If you need more room, you will have to delete something.

What's the difference between device storage and iCloud storage? - Apple Support

Here are some helpful articles that can guide you on how to free up storage space on your phone.

How to check the storage on your iPhone and iPad - Apple Support

Manage your photo and video storage - Apple Support

Clear Other storage on your iPhone or iPad - Apple Support

The storage on your phone is static. It can not be increased beyond the capacity it was purchased as (64/128/512/1TB gb). Your iCloud storage that you pay monthly for does not give you more storage on your device but allows you to utilize iCloud for device backups, syncing data between devices, etc. Since your device is low on physical storage you will need to make some decisions on what to remove to allow for my space on it. Otherwise you will need to get a new iPhone with a higher storage capacity to accommodate your data and usage. This is why I always advise people to not get the lowest capacity version even if they don’t anticipate needing it. Get at least the 2nd option because it should give you room to grow without worry especially if you tend to keep your device for more than a couple of years and prefer not to delete things.