hello, I'm quite new to gardening and I've made the mistake of overwatering my small cactus. I've had my cactus for about 5 months now and since yesterday I've noticed the bottom of my cactus is tinted brown and it's softer than the rest of my cactus. The cactus has tilted as well.
I cannot see an image. It looks as if the link leads to an image inside a zip file on your computer, and that will not work. The plant is probably a goner. If it had been a big cactus it would have been possible to save it by cutting away all the infected tissue and rerooting the plant, but small cacti are difficult to save. I usually resort to grafting when this happens to valuable plants.