In psychologically healthy people, emotions either give important information when our needs are not met, or they point to some unresolved childhood wounds/shadow. In the first case, I suggest that you learn to identify the emotion and connect it to an unmet need. You can then either share the emotion and make a request to your partner or others to meet that need, or explore how you can meet it yourself. My teacher Eckhart Tolle wrote: “When you complain, you make yourself into a victim. Leave the situation, change the situation, or accept it. All else is madness.”
In case of an emotional wound or shadow, you can welcome the emotion as an invitation for healing and growth. In most cases, the primary fight - flight - freeze emotion protects a more vulnerable underlying feeling (shadow) which in turn points to a false belief that creates a deep fear from the past. Once you identify this old fear (of being hurt again) that is no longer relevant to your adult self, you can begin the healing process through positive affirmations and introspection, or, in more severe cases, through psychotherapy.