At the end of the temple after clearing it, you're supposed to find the 2nd sword fragment of the stranger (exactly where you're standing on your screenshot).
After taking it, you're supposed to bring it back to Deckard Cain in New Tristram.
Here's a site that lets you check every step of The Broken Blade quest.
If there wasn't the sword fragment in Drowned ...
and says I can’t format it as an extended storage
This usually means that the drive is dead, as it can't modify the partition table or partitions themselves.
You can try to check if the drive works by completely wiping it via diskpart on Windows. This Seagate KB Article should help.
If the drive does not works on your PS4 after you wipe it on diskpart, then ...
The only way I've worked out how to do this, which would work for any game would be to load up the picture you want to save to your PS4 in full screen (remove any HUDs if possible) and then hit share and save a screenshot.
I had the same problem. I was able to solve it by lowering the air temperature in the room by about 10°C and placing the console on a cold marble plate to cool it.
You should also try placing the PlayStation 3 on the other side; for example, I always place it vertically, so I placed it down horizontally.