spoiler alert

That winter the wind blows I was so invested in this drama until the ending "i am still crying" :D

Please suggest me a good drama similar with a happy ending

You can try Sad Love Story ---> Sad Love Story
It's similar in the sense where the female lead is blind and the male lead isn't rich or better off than her....although the ending isn't very happy :P

There aren't many dramas that give the same vibe as That Winter The Wind blows though