so first you would want to try to research quite agressivly. in my experience, the first cpu will sell quite well, wich means i have lots of money for research and fabs. wich is both verry important. once you loose sales in your first cpu, then start singing contracts, watch out that you have enough production lines for the contract tough.
i belive i would be more helpfull if i saw your play style or when exactly you went bankrupt, but thats about how i doo it.
also, first like 10 years you dont want your cpu to have a cache. and check the cpus of the other companies to decide the pricing. (first one usually performs quite well when priced at 550 ~ 450)
if anny more problems arise, please make another comment