She left without saying anything to me. No warning or reason or goodbye, she left just like that. What should I do?

What really hurt is I was there for her through every hardship, I helped her in anyway I can possibly. She told me that I was really dear to her, and she really needed me. I helped in a way that nobody ever did for her. The way she was saying how she needed me I never thought she would leave just like that without saying anything to me. Now she doesn’t answer my calls or texts, She’s leaving the country next week but didn’t tell me, I found out from our mutual friend. Right now I feel hurt, manipulated and used. I want to move on but I kept remembering all the good memories we had together.