| Dear ladyecheveria, I think your plant may be Crassula dubia. I did a bit of research ... the following is a digest of what I have found ... i am no authority . Apparently Crassulas are notorious for getting fungal rust-type damage and need to be grown with protection from winter rains . But it seems plain your plant is sick and unlikely to recover, furthermore it may infect other plants. So the first thing to do if you want to try to save it is to dig it up pot it up and place it in quarantine. By all means try to strike a leaf, though this does not seem the best time to me ,it seems Crassulas grow in winter .But in our winter it may be getting too much water and hence higher humidity which would increase the liklihood of fungal infection. It would seem that you need take off those VERY damaged leaves immediately as they won't get better and then move it to an airy location with more sun. Soap and water is good for killing fungi so apparently is dishwashing liquid Deny it water for a month , then water from the bottom ie keeping the ariel parts dry eg. fill a saucer and let this be absorbed from the bottom for 15mins. Also I have read that as it is a fungal infection , you can wash the leaves in soapy water or dishwashing liquid ,[I would not let this soak into the potting mix ] and I would dry it off, alternatively you could apply some anti fungal preparation. I have also read a suggestion that "Perhaps a foot powder that claims to get rid of fungus, or Cinnamon" If it survives the leaves may remain scarred but in time they can be removed. If it dies well make sure you give your new plant more protection in winter , more light,sun and less water.
I derived all this information from simply entering the word "Rust" into the search provision on the Us forum. You should try it. One person seems to have had exactly the same problem I think her name was Brenda .. try contacting her directly she may have saved hers.
Regards,
Baldric | 
