I just felt that “ if she could do that to him there is nothing from stopping her from doing it to me “.
Your insecurity regarding this matter was, IMO, justified.
Anyway, sounds like you two tried for a year but in the end, you weren't a good match. I just broke up with my GF. We got along really well, never fought, loved being around each other, we simply had different long term goals. Because we both had instant chemistry together, we soon found ourselves thinking about long-term goals. I will always have nice memories of her though. But it is time for me to move on.
I think you did a pretty good job at being a good boyfriend. But from what I've seen (how my girlfriends reacted to how I acted) and what I read, girls want a nice guy AND an assertive guy who sometimes says "no". Some of them also like guys who are hard to get. Because guys are naturally attracted to girls, girls rarely have to work at "getting" a guy, and sometimes they like the challenge. It sounds like you were not "hard enough to get". But I am only guessing. And really, at this point, it doesn't matter. I think you will find someone where you both have the same long-term goals.
I have a long time interest in psychology, specializing in relationship dynamics for 30 years.
(Please note, we give the best advice we can based on the information given in a post. For better advice, please include the age of all romantic partners.)