What's the weather been like this year at your house?
At my house, I find that it's common to have years where the cantaloupe grow and not watermelon, and vice versa....
Here in ga, watermelon prefer dry years, and cantaloupe like wet years... In my experience...
As dry as its been here... I've actually been surprised that I got both cantaloupe and watermelon... Although.. My summer squash are puny.
So... Please describe...
Are you getting any fruit set at all?
One year here, my watermelons got almost ripe and then split open... Weather related...
One year the termites invaded my cantaloupe.... Mulch related...