This process is not made or broken on a simple text. Truth is she was temp checking you there. It's tough when down to your core you feel like you need to respond or justify your actions , so you replied with a "sorry I've been busy" which she seemed to reply "right... Bs but whatever" The push pull dance is tricky ... I took away from her initial text and seen it as her confused as to why you are not being her friend, because in her head and the plan she made out in advance had her leaving you but you both still being buddies. My w had the same fantasy .... A few well placed consistent truth darts solve this. My reply to such a text, "sorry if you feel I'm being short, I am just respecting the fact you want space and are going a different direction in your life, just as I am" validating you understand how she feels but also letting her know her choice will not land you as her buddy. Just my approach here
