The best advice I heard is don't change your header right now because blogger has fooled around with it and messed it up. If you
change it - it will become really little
and if you follow the same instructions
I did after going to the help desk here - it will become blurry like mine above.
If you google this problem there are MANY
articles telling you how to fix your problem.
I was able to follow instructions and get
my header bigger (instead of really tiny and only to the
left side of the page)
but I could not understand the instructions
well enough about it being blurry
and fix that.
Note from 11-2021 Suddenly
this problem was fixed by blogger!