There are many synonyms of happiness like pleasure, satisfaction etc. One that starts with D letter is Delight.
A synonym starting with d of the word calamity is 'disaster'
dire
Deluge
Disaster
disaster
Disaster?
"Disaster" is probably the closest synonym, but "distress" rather close.
Happiness, felicity.
One option is the word disaster.
Dazzling is a synonym for beautiful. Delightful is another word for beautiful.
overjoyed Euphoria Ecstatic
entertainment, joy, happiness, pleasure