How do I keep my emotions under control around my boyfriend?

My boyfriend is not comfortable when I am upset. He actually gets angry and uses a harsh tone with me when I am upset and it upsets me more and can actually be traumatizing to me. So when I am around him and feeling upset, I would like to be able to keep my emotions under control so that I don't trigger him and make the whole situation worse. If I talk to him about what I am going through, he starts to feel that it is boring that we are talking about emotions (especially if it has to do with the relationship) or he will feel that I need to be stronger and just let things go. But these words don't help me and make me feel worse, so I'm trying to figure out how to control my emotions. Because if I am upset, I am upset and I want to talk about it. I don't know how to just "let it go". But I don't want him to get involved and feel bad and make me feel worse. So how do I keep my emotions under control?
How do I keep my emotions under control around my boyfriend?
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