Sounds like you've regressed into some old bad coping mechanisms. So, would cancelling your appointment to avoid discussing these issues with your T just be another bad coping mechanism?

I have absolutely no experience with ED, so I'm just taking a stab in the dark here. If you want to turn things around so you can get back to handling life without pills or purging and so you can continue to be successful in school (a B+ is a respectable grade by the way), you are going to have to bite the bullet and talk about this with your T and get things back on track. Otherwise, isn't the danger that you continue to slide?