Hello! This is my first time posting here, and I would love any advice or growing tips y'all have.

I went on a small vacation recently, 4 days away, and when I got back home my cactus looked like the attached pictures. I've had this cactus for almost 4 years now and never saw this problem before. It was repotted for the first time a few weeks ago. I asked workers at a nearby plant nursery to repot it for me since I'm not a plant expert and don't have the required materials to transfer it properly, so I'm not sure what soil they used.

Help! What's wrong him? Is there any way I can fix this?

Sadly, your cactus did not survive the transplant. Its hard to say what went wrong: too large a pot, wrong soil, too much water...

It wasn't getting enough sun. The top should be the same size as the bottom.

Well dang

That's super upsetting. I do appreciate the reply, and thanks for the extra tip! I'll make sure to place my next cactus where it will get more sun.