Thanks Indi. I agree with what you say. It's true that character and habits don't change. But I do believe in improving one's own feelings and personality. I'm not expecting miracles or setting unrealistic expectations for myself or anyone, but, I believe there is always place for betterment, in everyone, if they see something they want to change and understand why they want to do it, then yes, I believe they can change. A person can always grow, and/or become more mature, if they set their minds to it. And umm, at this point, the conversation isn't even about my relationship anymore

-- it's about how one should always strive to be the best they can be.
I am not oversensitive in any other aspect of my life (studies, career, friendship, family) but in love, I admit it, I do tend to be. And it's something I want to change, not for my partner, but for myself. I can say that I am a lot more emotionally independent than I used to be, compared to a few years back, and I intend to keep becoming it more and to be happy this way.
And of course, if after I've tried again, we both really see that the "square does not fit the round hole", then yes, I will have no choice but to "save myself the longterm bother and move on".