iOS 16.5 is draining my iPhone battery

Can confirm: I performed a DFU (Device Firmware Update) and my problem is now solved. Prior to the DFU, not only did I have the battery drain issue, but my phone also ran warm. After the DFU, my battery is back to "normal" and my phone runs at a "normal" temperature.

As to my situation, I did NOT know what a DFU "reset" was, so I performed a search. There are several YouTube videos that explain clearly how to do it, so I just followed those. My steps were:

1. Perform a backup. I backed up my phone to my Mac, but you can use iCloud too. What I do NOT know, is if you can perform a DFU without a Mac. I suspect you cannot, but someone else with more knowledge can chime in. NOTE: my iPhone backup was encrypted and as it were, I had no need to use the backup for a really long time. I could not, at first, remember my encrypted backup password. It took me several tries to get it right. In light of my experience, I strongly advise you know what it is if you have an encrypted backup.
2. While my backup was performing, I watched a DFU "reset" tutorial on YouTube a couple of times.
3. Once my phone was backed up, I performed the reset. I got it on my first try, but it may take several tries to get the button combinations and timing just right.
4. Once I entered DFU mode, I selected "update" as opposed to "restore".
5. Once my phone was updated, I restored it from the backup I just made.

As mentioned, my problem has since been resolved.