My insecurities come from things that I was told about myself, either directly or indirectly growing up. I'm the least educated member of my family so I don't feel smart enough. My dad has told me all my life that I'm fat so I'm not thin/pretty enough. I've been used by people to get back at friends and then dropped at a moments notice when that friendship resumes which has led me to not open up as quickly as I would like to people so I appear cold and uninterested. I see other people around me who are able to hold it all together and who can apparently do everything and then I feel like I fall short because I can't. I've only been left for someone else once but it was for your typical bubbly little blond thing, so I have instant insecurities around my husband showing any interest in bubbly little blond things because the first thought always is that this will be the one I get left for because I'm not a little bubbly blond thing. So therein lies the source of my insecurities.
Everything will be ok in the end. If it's not ok it's not the end.