Any suggestions on how to cure insecurities?

Does anyone have any suggestions on how to cure lifelong insecurities? I’m sure many people have grown up feeling unloved, or not loved enough. So, how do you move into adult relationships and not need constant reassurance from your SO? I am in a relationship now and it is a self-fulfilling prophecy to feel that if I don’t get enough attention I am not loved enough and then him being annoyed with my mood when my insecurities flare up? Any suggestions on things to do? I’ve seen counselors before and I’m tired of just bringing up my past and nothing being solved.