Insecure about....everything

I'm insecure about....everything. I am not a fan of how I look in a dress, hate how I look in a swimsuit, and can't stand the way I look in general. I'm a quiet, suffer in silence type of girl and I make some regrettable decisions when it comes to trying to make myself less insecure... So how do I do it? How do overcome these insecurities? Please give tips in the comments!!!