This is the "frightened bird" case in love theory.
They don't get along well. They must have had many contradictions in the process of getting along, which led to their inability to get along. Once appreciating each other's advantages turned into nitpicking.
He met, experienced the ups and downs of love, and found that love was not as beautiful as expected, and his yearning for love gradually faded.
He got along with her, which made him know more about girls, stopped blindly appreciating the opposite sex and began to question such things as love. He wants to know more about each other with you, so as not to repeat the mistake of being together because of passion and impulse.
This kind of thing should not be rushed. You should get along with him as much as possible and let him know that you are unique. You are different from her.
Many feelings are together because they don't know each other, but separated because they know each other. That's not the love he wants. What he wants is a person who can tolerate his shortcomings, help each other and go further.
What you have to do is as follows:
1, keep an optimistic and cheerful mood and constantly output positive energy to him.
2. Show more other aspects of yourself, so that he can understand himself more comprehensively and accelerate his choice.
Be friends for the time being, and slowly heal his broken heart in getting along.