Pink Princess Plant looking sad

I bought this about a month ago, the woman who sold it to me told me to leave it outside until it gets cold and put moss in the tube to water it- I put it outside while it was warmer for literally two days indirect sunlight on my covered porch. it began to look like this so I brought it in. Ngl i gave up on the moss watering thing because i wanted to get it on the same schedule as my other plants. I water once a week with about a cup of fish tank water. She is not doing so well now... how can i help her?