Seems like he has psychosis and depression, which is something you can't fix by saying four words like “I was like you but I found friends and they cured me 🥺🥺🥺”.

Also, Naruto doesn't mean anything to Gaara since they only saw each other TWO times, and they didn't say that much to each other.

So this makes me believe that what truly changed Gaara wasn't Naruto’s words, but the head bump Naruto gave him. The hit was so hard that it even drew blood from Gaara’s forehead, and it is a fact that head trauma can lead people to change completely.

So I had this funny idea: what if Gaara, later on, was yet again hit in the head with such force that he returned to his unstable and psychotic personality? It would be soooo fun. Especially if he is already a father and a leader.