Help! Our favorite cactus is sad and drooping after a plant store repotted it.

Also is starting to grey from its trunk. Pot has drainage and we try not to water it a ton. I did bottom water it and it made it worse. Gets full sunlight.

Also is starting to grey from its trunk. Pot has drainage and we try not to water it a ton. I did bottom water it and it made it worse. Gets full sunlight.