It was not like Jiang Yuyan didn't trust Lu Qiang. She trusted him more than anyone, she could ever trust, apart from her brother. The reason she hurt him was when she saw Zhi Ruo and heard the word about her marriage with Lu Qiang, she felt bad. She was upset and jealous too. When she saw, Lu Qiang came with her to city S, she again felt bad but she gave a thought about it.
Jiang Yuyan was thinking about so many things since she was in Jiang residence for few days, but when she saw Lu Qiang and Zhi Ruo together again and the way Lu Qiang ignored her, she came to a conclusion. She was not jealous or upset. Instead, she was trying to be rational. She found Zhi Ruo worthy of Lu Qiang and thought he could be happy with her.