Sahir and Zeenat

He mentioned something about the person you love giving you pain. Maybe she had betrayed him in some way before the accident. Or maybe she was with someone else when accident happened.

Which also explains why Alvira, would rather see Sahir with Arzoo even if Zeenat comes back.

Somehow I think he loved her a lot and she betrayed him somehow before her accident, that's why he is coupled with guilt, hatred and pain.