That 's what I can remember of the plot

Two girls were switched at born. One is poor, smart, mean and live with her mother. The other one is rich,  not good in her studies, kind, have an older brother and liver with her parents. One day, the rich girl has an accident where her parents learn that she is not their biological daughter. Both mothers love their daughters even if they are not there biological one. The accident changed the life of the girls. Each one was returned to her biological family and the rich family moved to another city. After years, they met again. The fake siblings were in love since childhood.

It looks like the plot of Endless Love/Autumn in My Heart play by Song He Kyo, Won Bin. Great Drama although have a sad ending

Yeah they basically have the same plot but it 's not "Autumn in my heart". 

Maybe you mean one of the remakes of Autumn in my Heart:

  • Demi Cinta, a 2005 Indonesian remake starring Rionaldo Stockhorst and Leony Vitria Hartanti
  • Fall in Love, a 2011 Chinese remake starring Hans Zhang and Kiton Jiang
  • Endless Love, a 2010 Philippine remake starring Dingdong Dantes and Marian Rivera
  • Autumn in My Heart, a 2013 Thai remake starring Jesdaporn Pholdee and Sucharat Manaying, and produced by Ananda Everingham
  • Paramparça, a 2014 Turkish soap opera
  • Autumn in My Heart, a 2017 Cambodian remake starring Chhorn Sovannareach and Sokun Nisa

Thank you it's: Fall in Love