I need unbiased third party opinions.

I am 27F in long term LDR with my bf of same age. I am a 1.5 gen immigrant so i am comfortable with both cultures but personally, I feel less connected to my country of origin than my parents do. My bf is from a different cultural background, and my parents have enver been happy about our relationship. He is also my first boyfriend. 

Background: In the first two years of my relationship, my mom and I have only fought about my relationship. The first and second fights was because I slept over at my bfs house without telling her. Third fight was because I wanted to bring him to an important event in my life. Over time, I started hiding my relationship from my parents to avoid conflict, which also meant I rarely had the opportunity to share anything about it with them. 

Most recent conflict: I told my parents that I am going to my bf’s friends wedding. I told them for two reasons: 1) I wanted to be more open about my relationship to my parents and 2) I share location with my mom so it would have been difficult to hide this from her. My parents were shocked because they thought I had broken up with him. We had a long conversation about their disappointment of me jumping such a big event on them, how i need to marry a “similar” man (not just in the sense of ethnicity but also in terms of socioeconomical status, family dynamics etc) and my mom even asking me what I'm going to do if she asks me to choose between her and my bf. 

Couple days later, she sent me a long email detailing her feelings. In a nutshell, she told me that while I am an adult, attending a wedding as someone’s partner is a decision that should involve the family. She believes that the fact that I have to stand up for my relationship is a sign that it is the wrong relationship, and that my boyfriend's willingness to remain in a relationship that she disapproves of is disrespectful to her. She also criticized the way I communicate, saying that simply informing my parents of decisions I've already made is immature. She urged me to have more pride in myself and find a respectful relationship where I don't have to "defend" myself. She did apologize for some past behaviors that I have told her hurt me, although I'm not sure she fully understands why those situations affected me the way they did. 

What I'm struggling with: On the surface level, this may seem like a straightforward parents disapproving of their daughters relationship, but I really think this is something larger than that and feels like it will repeat if I am to do something in the future that will go against their wishes. My parents for the most part have let me run my life the way I want to; however this often came with me having to push the decisions against their negative judgements and me having to prepare knowing that these judgements are coming. There have also been instances where i made a decision and just told them and they were okay with it, presumably because it wasnt a “bad” decision at the end of the day. 

I recognize that I'm not the best at sharing about myself, particularly to my family, which I think contributes to this situation because my parents seem to interpret it as another increasinglyg inappropriate decision. I understand some of my mom's concerns about compatibity and making thoughtful decisions about life partner. I also understand why she might feel hurt that I haven't been open with her. At the same time, I struggle with the idea that decisions about my relationship need to involve my family’s approval, particularly when our expectations about dating are so different. Things like staying overnight, traveling together, and potentially living together before marriage are things my parents never even thought about doing before marriage, and as a result, I feel like every new milestone becomes an ultimatum to them even when it feels like a normal progression of relationship to me. 

The “smartest” and easiest way out of this would be to break up. But I love my boyfriend very much and I don't want to end a relationship solely to avoid my parents' disapproval. He is so emotionally mature and I have never felt safer and like my true self than when i am with him. We also have amazing communication which i have felt time and time again. I also worry that even if I broke up with him, these same conflicts would resurface with a future partner, especially if that person comes from a different cultural background. 

I am lost on what to do. I am scared that I am making the wrong decision, especially further damaging the relationship with my parents. Do I go to this wedding? Is there anything I am not seeing because of love? Is there anything I can say to my parents that would help see this situation more clearly? What can I do to handle this better? I feel like my parents are pretty reasonable human beings so i think it just makes me doubt myself even more. I would appreciate any insight and tips on what to do short and long term. I almost feel like there is no way to for my parents come around on this relationship at this point.

tl;dr: 27F dating someone from different cultural background and my parents disapprove. after years of hiding my relationship to avoid conflict, I told them I'm attending my bf's friend's wedding, which sparked another fight. I love my boyfriend but worry about damaging my relationship with my parents if I attend this wedding and continue this relationship.