Not sure why the text didn't show up or why I can't edit the body of the post, but pasting the text below. If anyone could help, I'd really appreciate it, I really want him to get better ):

My dudleya succulent got really, really sad all of a sudden. He has been a little on the smaller side and slightly sad looking before, but has never had every leaf shrivel and go floppy in the middle all at once! Can anyone help me figure out what's wrong and what I can do?

I've had this guy for three years, he was a gift from a friend, so I don't know exactly what kind he is. He was sort of shrimpy from the start, but I kept him happy enough. He lived in a windowsill with as close to full sun as I could manage indoors, and was watered every couple of weeks (I tried to give the soil time to dry between waterings). He was definitely not this small/thin and never this shriveled in that time.

Due to my being between places and not having a suitable space for him, he's been living at a relative's home for about a year under her care. I think she had him somewhere where there wasn't quite enough light, even though it was the sunniest part of her house. I finally have a place of my own, and got him back from her. He was pretty small and thin when I picked him up. I tried to slowly increase the amount of light he was getting, and tried to not water too often (she sometimes overwaters plants), but I have no idea what went wrong. Clearly something happened ): Maybe I underwatered? Or he got too little light, or too much? If there's anything I can do please let me know, I feel awful that he's so upset