Crush confuses my behaviour

Hi guys I am 18. When I get a crush on someone, my behavior starts to depend more and more on them, results of interaction attention they give me or things like that. And this makes me feel sad or happy but more importantly makes me do stuff sometimes not respectful towards they or also other people. For example I cannot stand my sister like I cannot tolerate her. Fundamentally I am less conscious, and less present. I don't know. Any help would be appreciated ❤️