I think it's admirable that you are going to therapy and continue to do so. Even though you feel low afterwards, you haven't given up and you mustn't. Overcoming an eating disorder is a struggle, it's a mental fight all the time I'm sire. I don't understand how it feels fully to be honest, I haven't been through the same. However, if I treat this as any disorder where you're fighting against your own mind, I can feel that. And I can tell you that it's hard but you must take it step by step. Every therapy session is a step..and once you've taken many steps or sessions you will look back and see how far you've come. And to be sure, the path doesn't have to be linear, you may have to take several loops and diversions, retrace your steps to reach the goal. So carry on and don't be disheartened!
Therapy is not always a linear process. The purpose of therapy is not simply to make us feel good. What that means is that while we may walk out of some sessions feeling happy, hopeful, calm, sometimes we may end up feeling deeply troubled.
The main reason for this is that we are in therapy to untangle the conflicts both internal and external that we are struggling with. So sometimes what realisations we have may make us feel better, sometimes we may also be confronted with aspects of ourselves that we are troubled by.
I would say, don't let these moments make you loose hope. Personal growth is a slow process. But it is also difficult and painful sometimes.
With that said, our feeling low may not always be because of this reason. Sometimes, we may be continuously feeling low because we are not comfortable with our therapist or perhaps the model of therapy they use may not be working for you. Either ways, what's important is that you voice your concern to your therapist.
The client and therapist relationship is grounded in genuineness. So if you are feeling something, don't hesitate to bring it up with your therapist, simply because it may not 'sound right' or perhaps 'upset' or hurt them .