I've had this cactus for over a year now and it's been in the pot it's in for quite some time however in the past few weeks some of the larger pads on it have stated to warp and bend whereas before they stuck straight up. I did cut off a few of the pads propagate them a few months ago but since then the new growth on this cactus has been a yellow-green colour. I'm not sure if it's lacking minerals or something.
Anything I can do to bring this guy back to life? Any help or advice would be appreciated thanks.