"falling apart"? Literally coming to pieces? Perhaps you could post a photo, or give a better description - if its what's known as an Easter cactus, bear in mind most plants look a bit tatty when they've just finished flowering - they're exhausted!

agree with Bamboo a picture would help. My cactus has finished flowering now and looks drained. I will feed mine with a little baby bio, to perk it up again

i can't do a photo but thank you for all your help i will feed it as it was a easter cactus from my sister thanks again sue