Wow - congrats on your 30 year old Christmas cactus. I suspect it is still recovering from the shock of the transplant so it is blooming less but if the branches are falling off the plant that could be a sign of overwatering or poor drainage. Did you use a quick draining cactus type soil when you transplanted? Make sure the plant never sits in drainage water and if the soil is consistently moist to the touch I would remove the plant, use a container with more drainage holes and repot using a quick draining potting soil made for cacti and succulents. You can take cuttings of the mother plant or try to root the branches that are falling off by sitting them in a glass of water until roots form. This way you have a back up of babies just in case the mother plant fails to survive the second transplant. Like most succulents this houseplant needs to dry out between watering and is not a heavy feeder so use a slow release plant food like Osmocote only once a year and at half the recommended strength. Keep growing, Marianne Binetti