I did an online chat with an Apple senior advisor last night. After making sure I backed up my phone, they had me reset my phone. Sounded scary to me but it worked! I was told after the last update (to 13.6) I didn't have enough room to complete the update so it corrupted my system to the point where deleting things didn't do anything. Here are snippets from our conversation:
For now, the next step is to erase the phone, via Settings ->General->Reset->Erase All Contents and Settings.
During the restore process, setup the phone manually, Do Not Transfer Apps and Data. Tap Forgot Apple ID or Password, then Setup later.
When the phone is in the Home screen, check the storage.
(My storage was freed up at this point so he said the below)
I'm going to ask that you please erase the phone once more. During the setup process, choose to Restore from your iCloud backup.
He also suggested to always leave 2 GB of free storage for the phone to work properly.
Hope this helps!