Sounds like too much food to me as well.

Most Dendrophyllia species take several days to digest their food. You can see them go through different "phases" while doing so, based on tentacle length, thickness, etc. No need to feed more than a couple times a week.

At this point you'll have to let the dying tissue recede and die off, and hopefully some tissue will remain. If it does it will develop a new polyp and grow again, although it will take a while to come back to full force, and it might actually just develop several smaller polyps overgrowing the original one. The baby polyps you mention should probably be OK.