Gojo said "The only one I have", but according to the official translation, he said "My one and only". For how many months after reading it, I decided to reread it again and started to get curious what does it mean and finally I have the answer.
"My one and only" is a strong way of expressing your incomparable love to someone. It also means 'The only one for me' and 'the only one I will ever love'
GOSH MY SATOSUGU HEART IS SHAKING
MOVE BITCH, THAT MAN IS IS TAKEN ALREADY SHOOOOOOOOOOOOOOOOOOOOO!!!!!!