Issues with being blunt and petty

Hello everyone,

I'm new to these forums and am looking forward to learning new ways to improve my mental health and way of being.

I've always been an honest person. Over my life, I have always come off as blunt and sarcastically blunt with only my immediate family calling me out on it. I've never really thought of it as being an issue, but it has become one recently with a woman that I have sexual relations and have a deep connection with. She isn't my girlfriend, but I really wish she were. I've noticed a lot recently that I always become petty and blunt at times when I feel I should be getting something I deserve or someone doesn't act the way I would. For example, this morning I was leaving her place and wanted to kiss her goodbye. She didn't let me because she was afraid I was going to notice her morning breath. I replied to the notion by saying, "you're always making excuses." I realize now that this was insensitive and is actually a sensitive topic since she is working on trying to better her self-confidence and trying to finish school.

I've always told her that I don't want to hurt her but I feel like I'm being toxic in her life with my words at times. I feel like such a hypocrite and want to address my pettiness and bluntness. I want to be better but don't know how to change the way I communicate with others and my personality. Additionally, I have lots of anxiety at the thought of losing her. My closest friends describe me as a genuine person, but I see my flaws and think otherwise. Any insights or resources would be helpful. Thank you.