Don't worry, we will always be friends.
Don't worry, I know what you're going through.
Don't worry, I will always treasure the times we have shared together.
Don't worry, I will only be gone for a little while.
Don't worry, I will always remember you.
Don't worry, this is not the end of our friendship.
Don't worry, I care for you.
Don't worry, I will come back for you.