He was so close to her but due to a lot of pain he went through he did not wanted to have hope again.
But just when he realized she is there he did not left any stone unturned to make her his again.
Preface: What if Naira had decided to go to Singhania's instead of faking her death after Kartik's question and the car crash?
My take on the separation leap because the five years track did not sit well with me (as it didn't with most of us, I'm sure).