Alas, my girlfriend was chatting well on QQ, and suddenly she sent me a message saying that she was gullible and that no one would be there if I didn't want her.

She probably cares too much about you. She is angry because she said so many heartfelt words to you, but you said things that didn't make her happy. Later, during the period of cooling down, you still didn't say anything. She was afraid that you would think too much, so she explained. In fact, you just need to coax her, comfort her, tell her what you really think, and influence her with your heart, and she will understand your mind.