Hi,

First of all, thank you for your reply. Let me do as you say. Shall I continue to water and light the plant during this period?

stop watering altogether for two weeks after you cut off the leaf. this will allow the roots to heal the rot. if you start watering again and another leaf rots, the plant may be done for

Sure, will do. Thanks.

These do not need much water.

Is there a problem with another leaf - very right of the photo? Not sure, but it looks like some spots are there too.

IMO, self-watering pots are not suitable for succulents. These plants should be potted in fast draining mix and in containers with drainage hole. I believe your plant has been kept too wet.

It happened to two more leafs after the one in photo.

Pls excuse me but you are drowning the plant.

Several people have told you what to do. May I pls. be direct, you're plant is critical, if you do nothing it will almost certainly die as it appears to be rotting!

apachekumaran, to answer your new question, yes, your plant needs a normal pot with a drainage hole and saucer once it's stable (e.g. the soil has been dry and the rot stops spreading). Replanting it might be too stressful, but it's probably a toss-up between leaving it in place while waiting for the soil to dry out vs. disturbing it while getting it into a better pot and dry soil right away.

I'm sure someone with more experience than I have will pipe in about
which is better, and what kind of faster-draining soil this plant will
be happy in.

I don't know how your pot works, but if there's any excess water in a reservoir it needs to be drained right away, and in the future make sure that your plant's soil doesn't come in contact with water that has drained out (that is, no standing water in a saucer)

As an aside, don't rely on what a potting soil's bag says; many soils that call themselves fast-draining actually stay soggy if watered on a schedule, instead of when the plant actually needs water.

Plant will probably not recover where it is now. If there is any rot in any part of the plant, it could be spreading thru the plants leaves, roots - without being visible right away. It has been suggested by few posters to get it out of the soggy soil right away.

When you re-plant it, pls. do not water it, so you replant it dry.

Then wait another 2 weeks as suggested above before giving it any more water & hope for the best.