I'm in love with my Ex best friend

Abby and Sabastian were best friends up until the first day of high school. Abby had no idea what she had done for him to all of a sudden stop talking to her but it had torn her apart. Now after 4 years she has been able to handle it better then she first did but she still can't shake the feelings she has for Sabastian all she can do is hide them and she has become really good at that but when things start to change between Abby and Sabastain will she able to handle the possibilty of getting her heart broken all over again?