In general we are taught to follow the “golden path” of balance in other emotions and character traits. With two exceptions. Anger and humility. One should try to stay as far from anger and haughtiness as possible, since these are traits that are the antithesis of how a person should be.
However, while our Talmudic Sages describe anger as being one of the most destructive emotions that a person can experience, there are certain occasions when a carefully controlled outward show of anger is legitimate and, perhaps, even recommended.
I think an important question that only you can answer is whether any of the cases of anti-Semitism you have experienced has warranted an “angry” reaction, and even if they did, whether your anger actually achieved anything. From my own personal experiences, I have found that most times anger has not worked and only exacerbated the situation and made it even worse. On the whole, I think that trying to open a dialogue is more productive, and if that is not really a viable option, then to follow the advice of our Sages and to remain quiet.
