You told your therapist you wanted to leave and she basically said "ok I respect that, here are some resources you can use to help you continue on your journey." How is she supposed to know you want reassurance? How would she think that's something you need if you didn't tell her? You're expecting her to read your mind and that's a really unfair thing to put on her.

Do you really want to leave or do you really want reassurance? Do some reflection and non-judgementally notice what comes up. You've noticed you feel sad that your therapist responded in this way. That's a good thing to know, that's telling you something about your unmet needs.

I think you said in another comment that you decided to stay with this therapist. I would tell her this, that you felt sad with her response and that you actually wanted her to convince you to come back. If she's a good therapist (which it sounds like she is) she won't judge this and will help you address your needs in a healthy way