How can you calm down insercurites?

Your boyfriend is with you! He is not with anyone else so it means that he only cares for you. He loved you before the other girl and he is with you know, he left you for that girl. You shouldnt have an ounce of insecurity because of an ex. I bet his ex gf felt so dumb the day that you two got back together. I know if my bf got back with his ex after we broke up i would feel like our relationship meant nothing, he clearly never stopped liking you. My bf ex is really gorgeous and i can't stand it but honestly my bf chose me and weve been together for almst 2 years now and i know that if he wanted her then he wouldnt be with me.