Did you raise the silkies on chow or on leaves? Some of those problems could be due to chow if you are using it. If you are using leaves, then make sure they are always fresh etc. Also, get a good strain of silkworms. I don't remember any casualties from my cocoons and I hatched around 20(I did get a very tiny female who laid maybe 40 eggs total but that was probably due to feeding or odd genetics).
I know of some people who may have extra eggs. Specifically, look up the Catherders mailing list. I need to hatch mine after killing the early summer batch.
Also, in the future, any silkmoths that emerge without mates can be stuck in the refridgerator to prolong lifespan by slowing down metabolism.