ANSWER
–“how much can you trust a feeling?”–
1) All emotions are reactions to change in state of ‘something of value to you’ (an asset, a demonstrated interest) whether potential gain, gain, retention, loss, potential loss. And whether the form of our body, action, time, habit, knowledge, relationship, thing, association, organization, commons … anything we have an interest in. (interest in the legal sense, not in the mental sense.)
2) We may correctly or incorrectly interpret the legitimacy of our interest in (right to) what it is that we value whose state is, or may change.
3) We may correctly or incorrectly morally and ethically interpret the legitimacy of ours or others’ interest in (right to) what is changing.
4) In the sense that you ask the question, ‘Can we trust our emotions?’ we can trust that they are caused by something or other that we believe has changed state (most often our status or self-image than anything else, since status and self-image largely determine access to opportunities), we cannot trust whether these emotions are ‘true, useful, ethical, moral’ practical, or selfish, petty, childish, immature, antisocial, criminal, or evil.
5) We are different from chimps (and they are not good, kind, or nice or virtuous creatures by any means) largely because we have developed sufficient agency (self-reflection and impulse suppression) so that we don’t retaliate against anything but that we must retaliate against given our environment.
-Cheers