Yes, this is absolutely a case of overwatering... the leaves are drooping AND quite swollen with all the water in them. It's good that you've stopped watering... let them dry out completely before giving them anything more - and each time you water or feed, always make sure the pot is super dry and needs something. In order to make sure you're watering thoroughly, though, you will want to see some running out the bottom of your pot. I always put a saucer underneath and let the runoff stand there for 15-20 minutes as sometimes, if the soil is REALLY dry, the excess water will be soaked back up into the soil... then I water it some more and keep doing that until no more water is soaked back up and I throw the excess water away. This ensures there are no dry spots in your soil... roots, if they hit a dry spot, will simply stop growing... But always, always, always make sure your pot is dry before giving them more....
Good luck!