woh well you have missed a lot...the best thing to do is to probably read the updates but to make it easier....here's what happens:
Kusum lives with Abinav and she takes care of the child and then both of them(the child and abinav) go to the US to get the child a better treatement and Mahi gets Swati(kusum's lookalike) and brings her to the Kapoor house on Karvachuth and kidnapps the real kusum. swati shots abbhay on that night and pushes him in the pond. abbhay gets paralyzed and mahi and swati give him the wrong medicine the whole time!!! then when kumud finds out that kusum is not kusum but she is swati, she gets kidnapped. then on kali's reception, kusum saves kumud and mahi drowns abbhay but kusum(the real one gets accused) in the middle when kusum escapes, swati gets shot!! so this is it and if you need anything else just tell me!!!