Insecurities

I wonder if anyone else here is dealing with insecurities. I've had this issue ever since I entered middle school. Like never satisfied with your body or appearance in general? I'm 106lbs but I keep wanting to lose weight even though my bmi would be fall on underweight side, same goes for height I'm 5'4 but I always felt short. and things like that. Anybody else? How do you manage it?