Honest to God, this is the way people from Tennessee, north Georgia, and most of Alabama sound. Study this if you want to have Southern characters in your books.
BTW, as my husband points out, you can say the meanest, cruelest, ugliest thing about a person, but appending “bless her/his heart” to the statement makes it completely okay.
“Bless her heart, but she was dumb as a box of rocks.”
“He’s ugly as sin, bless his heart.”
You can also use it to show general sympathy. “I fell off the roof yesterday.” “Bless your heart!”