Storage problem in Marshmallow
Format as internal sets the SD card up in such a way that to apps it appears as internal storage, effectively replacing you internal storage:

How does the &quot;Format as internal storage&quot; feature work in Android 6.0+?

So of course you internal storage appears full (As everything is now stored on the SD Card), and of course you have no options to move stuff to your SD Card (As everything is already there, and it is being used as internal storage).

Your SD Card is 16GB I'm guessing? Of which 7.3 is used up by apps, games, pictures, etc (Your 'internal storage'). Your internal storage is reported as full as it can't be used.