Can anyone give me some help with a Christmas Cactus that I have. It´s many years old and has been dropping leaves. I think that I have been over-watering but it seems the underside of many of the dropped leaves have a several gold-colored "blistered" looking spots on them. Many dropped leaves look wilted and bleached out a little. Any suggestions?

A few weeks ago I repotted it because the soil was solid like cement. This leaf-dropping problem was going on before that but has increased. I hate to lose it as it has been in the family for years. It has a number of new leaves on it but is gradually becoming smaller and smaller because of the number of dropped leaves.

Is it good to have it outside during warm 60-70 degree weather or should I keep it inside and out of the sun and cool nights? Can this problem spread to my other Christmas Cactus?

Tack för hjälpen!!