The Concubine's Counterattack: the Emperor's Exclusive Favor!

[Rebirth + Revenge + House Fight and Palace Fight] In her previous life, she came from a wealthy family, and had studied medicine for generations. She had a close friendship with the middle palace, and was even a childhood sweetheart with the prince. After he ascended the throne, he entered into a marriage contract. The beauty was a perfect match in terms of talent and appearance. Her husband doted on her and she was pregnant with Liujia. As a queen with a simple mind, she and her unborn baby were poisoned to death by her most trusted sister, but the culprit replaced her as queen. Decades later, she was reborn as an unpopular concubine. Her fiancé did not take her seriously and secretly colluded with the sisters in the palace. The mistress had the power over the palace and wanted to kill her without a burial place. The concubine who once betrayed her has now naturally become the queen mother, enjoying the most noble position. It's obvious that it's a trap within a trap, but I can't get out of it, and I'm getting deeper and deeper into it.