Insecure...

I just turned 17 and I'm 5'4 and 170lbs.  I feel fat most times and I feel as if I'm too big for my height and age.  I work out often and try to keep good eating habits but I still feel like crap about myself. I constantly compare myself to every pretty girl I see.  No matter their height, age, or weight! I try to tell myself that everyone is different and unique and beautiful in their own way.  But it's a constant argument with what I want to believe and what I truely think about myself. I'm here looking for advice on how to love myself and possibly some motivational tips to help me lose weight. I want to be healthier and happier. Any advice?