Hey,
no worries, I think every breeder probably kills more larvae and beetles, or does not get eggs, or larvae to pupate, than they have successes. Of all the beetles in the world, even within Scarabs, only very few are actually relatively easy to breed.
Also, you should not believe everything you read about successes. I think you did well with tytius. you have enough larvae to get a good number of imagines in the next generation, to try again either for more eggs, or for bigger sizes.
That said, I would rate Chrysina as a very complicated group, even if you do all the things mentioned in Orin's book, you do not get successful in many cases. The question to ask here is, who of all the breeders of Chrysina is actually past F1? I believe the majority of larvae sold are offspring of wild-caught females, and the absolute minority are actually captive bred second, third etc generation. I do know a lot of beetle breeders, but Chrysina did not get established in their breeding rooms, for the above mentioned reasons.
Another advise, even though that's hard to keep when you are just starting, is to leave the larvae alone and let them do their thing, check them once a month, and only to see if there is still enough substrate. That normally does wonders already.
Hope this helps!
Cheers
Ben