Papayas grow a long tap root, and for that reason, they don't like to grow long term in pots. They also really don't like "wet feet" so if you are watering, and there is water pooling in a saucer or around the base of the pot that also wouldn't be too great. I'm sure you're having to water that baby pretty often with warm weather like that.
A bigger, deeper pot might help things short term, but in truth, the plant's not going to be happy too much longer in a pot so you need to scout out a place you can plant it in-ground somewhere. Or I did see one fellow that got a 55gal. drum (not oil, though, a food-grade barrel) and made it into a very large, deep container for a papaya. Lots of drainage holes in the bottom, cut off the top, well-draining soil and a place where it won't get blown over are needed to do this.
