Emotions are natural to experience. They come and go all the time, and that is perfectly normal. Emotionally intelligent people recognize this and function well in life. They understand that it is not about not having an emotion, having less of an emotion or not expressing it. It is about how you express the emotion, where you direct it, and what you expect of your loved ones to do about your emotion.
Emotionally needy people, on the other hand, make up drama (to draw attention to themselves). This of course repels the partner (no one wants to be around drama). The partner withdraws (attention is not achieved) and the drama gets bigger. Now the emotion is not about the original thing but about “my partner not paying attention to me and not getting me, therefore I am not important” (classic victim mentality, often coupled with narcissism).
On the face of it, one should be very discerning about their emotional behavior and always make sure their emotional needs are valid and they are not just dumping their shit onto another person. Valid emotional needs are centered on emotions that are completely internalized and taken full responsibility for. You get angry (with or without your partner being around). You take responsibility for your anger, and you realize that you are in charge of expressing that anger appropriately. You may need to talk to someone in order to assimilate what this is all about. But pay attention to your motivation here. Are you initiating communication in order to understand anger, experience it in a mature way, and release it? Or are you initiating conversation to draw attention to yourself and your problems and to elicit sympathy so you can feel special and loved? Are you making this about yourself and picking up a fight with an innocent person? Or are you trying to neutralize a charged experience in a responsible way?
If you are being mature about your emotions, then it is absolutely appropriate to want from your partner to meet your emotional needs (by listening and perhaps reflecting back some neutral observations). If your partner can't be around your intelligently expressed emotions, then it is absolutely reasonable to seek out another partner.
However, if you are trying to draw attention, create drama, and make someone else responsible for what you are feeling, we are not talking about natural emotional needs here. Rather, we are talking about emotional neediness which, frankly, no partner could ever deal with. You need a therapist instead.