Hello, I'm pretty new to succulent and cactus care. Here I have attached a photo of one of my potted succulent plants. When I first got it, the leaves were angled upwards, but since November or so, the leaves started drooping like this. Some of the leaves have even dried up and fallen off. You can see one of the leaves on the bottom also starting to dry up. What can be the issue?

I water lightly only about once a month. The other cacti in the pot are looking healthy as well. It is kept next to the window in a room that is around 66 to 67 degrees. They were bought about 4 or 5 months ago and were re-potted after taking them home.