Hmm, most of the leaves are dead or dying. I see on small one in the center that looks healthy, though it might not be either.
Cut off the dead leaves. You can take off the flowers too, or leave them until they fade if you are enjoying them.
With the dead leaves removed, examine the tuber. Is it solid, or are their signs of rot and decay?
If the tuber is okay, continue to give the light, drainage, irrigation, and fertilizing asdescribed above, though both irrigation and fertilizing should be reduced until new leaves grow back.
How long have you had the plant?
At this point the size of the container is not a problem. The potting soil is the kind that dries out quickly, and it will would also drain well, as long as the container drains. Are there drainage holes on that outer red pot? Perhaps take the inner brown pot out of that red pot.