I'm looking for this one CN BL about a doctor that transmigrated to ancient times. He was forced to marry a weak prince who has poisonous blood due to getting poisoned by many people over the years. Also the MC has a grandpa that was known as a very knowledgeable doctor and was rumored to bring back the dead (If I remember clearly). Oh yeah, the MC also has fast regeneration powers too and the novel was placed in Hiatus from what I remembered.