Hi Ousaima,
yes also nail-biting fits the aggression-against-self (which is a territorial cortex constellation namely of "territorial anger" and "identity quest" with more conflict weight on the right hemisphere, thus suppressing the male hormones). By that, aggression against others is inhibited which is often seen together with depression. We'll cover the cerebral cortex and its specialties soon in the course!

We want to differentiate thoughts and beliefs from feelings. We can feel disappointed, we can feel pain, but "I can't do that" is rather a thought that can turn into a belief. Because you might be able to do that in another way, or with more practice. One magic word to add can be "yet" - "I can't do that yet". Which is just the point you're at, but without devaluation or prognosis.

Eve's case isn't yet clear regarding what the original conflict was, it wasn't ready to be revealed yet, but the attached belief is very strong, showing that there is a big conflict weight. And the weight is (always) connected to feelings (i. e. sensations and emotions). That's why we want to work carefully, respectfully, persistently with these, until it feels safe for Eve's bodymind to let go of the "tight belief".