Stuck in a shell of myself

I (19f) don’t want to have to keep being this shell of a person that has to uphold this image and attitude to be liked or look a certain way in front of people. I was really hurt when I went through my first breakup, and it triggered so many insecurities for me. I constantly felt like I had to hide that, or that I had to be okay, not care, and get over it. And it made me feel like I had to change so much and like there were only certain parts of me that were valuable, and that weren’t valuable. I felt like I was not enough at all in the person I was. Plus I was. Constantly around him and his family so it really made me feel like I had to put on this personality that was attractive, and not like I was upset or hurt. So it made me feel like I had to push it down and numb myself, but there was still so many feelings under that, and I had to learn to live with that for a while til it just eventually became a habit for me. So now I have a habit of putting on this front to seem a certain way for them and I hate that I feel that way, because I feel like I even have to do it in thought of them. I don’t really know how to handle it besides cutting them out, but it’s more so of a me thing and why I still feel the need in my mind to be that way. Is it insecurity? I think it’s a big part of it, and also shame and embarrassment maybe. But I feel like it’s taken up so much space in my mind that it makes me feel numb to how I used to feel before, and not even necessarily numb, but just different. I think differently than I did before and I feel stronger insecurities. I just wish that breakup and the aftermath didn’t have that big of an effect on me and how I feel about myself and how I have to be. I want to change my mindset around, and I don’t want to keep making these people the center of my life or fear looking insecure or bad around them. I just want to feel free again and like I’m not holding myself to anyone’s expectations or trying to put up a front for past reasons.