@Kimiya78
Indeed, I don't think he ever really decided to pursue Xiao Yao. There were a few times when he almost lost control, but in the end he managed to bury his feelings for her happiness. This is also the admirable thing about Xiang Liu: he doesn't get entangled, doesn't backpedal, only gives companionship, doesn't give torment. He doesn't easily change things he has decided. Finally he achieved the happiness of the one he loves with unbelievably strong will.
But yes, he still needs Xiao Yao's company. Before Xiao Yao left Qingshui Town, he had allowed himself to be emotionally attached to her, because in his original plan, Xiao Yao would accompany him in his life until his death. Xiao Yao has promised to be "his man". To him, this is a committed relationship. He even sent a congratulatory gift to her on Ma Zi's wedding day. When Chuan Zi's marriage was blocked, he made the decision without hesitation to settle it for her. Because she is "his man". Moreover, Xiao Yao told him that she would rather die than leave Qingshui Town. How could he know that one day she would choose to leave forever?
And, I think there are two main reasons why he pretended to be another woman while on that ship. The first one is to listen to Xiao Yao's inner thoughts as a stranger, the most important of which is of course the reason why she doesn't go home. Did you notice the urgent, exasperated tone in his voice when he asked her why she wasn't coming home? :-) The second one is my personal opinion, that Xiang Liu had been angry since they parted last time. He went all the way to Wushen Mountain to save her regardless of his own safety, and was injured, but found that she was with Jing (in his arms, hugging his neck). She had clearly asked him for help before, but now she has Jing, so "I don't want to owe you", she even said it in front of Jing. How could he not be angry? But even though he was angry, he still missed her, and when he saw that she was going to take the boat, he couldn't help but want to see her. But how can our proud Lord Xiang Liu admit this? impossible! It's someone else you're chatting with, but Xiang Liu hasn't forgiven you yet!
Then I want to explain another point. Regarding the reason why Xiang Liu was so angry after knowing Xiao Yao's true identity, realizing that she would never meet him again was just one reason. Another important reason was that he couldn't bear that his feelings for her was based on a bunch of lies.