I have a leggy / droopy Peperomia argyreia aka watermelon pepperomia. It's in a 5 inch pot with houseplant / topical potting mix that sits in front of a southeast facing patio door that has sheer curtains all day. The plant is watered when the soil is dry. Room temperature is about 70F. The plant produces small leaves which mostly just shrivel up and die. What do I need to do to have a healthy plant?