How do I work on my sensitivity? Is there a such thing as being too sensitive?

Lol you guys, I've only been with my boyfriend for 3 months and I'm already extremely attatched to him like ughhh. Today we had our first war, I mean like we argue all the time but this time I felt like it was some serious shit cause there was a female that comment under one of his posts and it kind of looked like he was flirting with her. So I obviously confronted him about it and he was just saying he didn't want to argue with me .... I felt like that was something to argue about though so basically he ignored me and all of my calls which I called him 50-60 times in a row and because he basically ignored me I cut myself and even cried myself to sleep. I literally was this huge emotional mess and I felt like dying. Like honestly I've always been this way. I blame it on my Zodiac sign (I'm a Pisces) So here's the thing. The whole reason he ignored me was because he was trying to teach me a lesson about arguing over dumb shit especially when we have so little time together. So yeah he did that without knowing how sensetive I am and now I feel crazy as hell. Is there a such thing as being too sensetive? Should I work on that? Could it jeopardize my relationship?