Calicoe, I totally understand and relate to your feelings of hurt and insulted trust in both cases. I do agree that your flatmate must have been triggered by your disclosure, but her behaviour in the whole context does sound rather selfish, and that would make me feel angry too. We sometimes find that people's limitations prevents them giving even what we've given them and thought they were equal to.
Please don't remain offended, though, by the apparent comparison that was drawn. It's quite understandable that it would outrage and hurt you and you are right to express that, calmly as you did. But it would not have been meant personally or to actually compare you ... there is no comparison - we all know that!
I hope you can have some kind of progress in the relationship with your flatmate ... And I send you encouragement (I think you've handled things well)