REALLY Insecure about my boobs

I have kind of saggy boobs with big nipples I'm really insecure about them how can I change the way I think about myself/starting to love myself more?

Like I always wear bras in public cause I'm scared that people will judge the way they look but when I'm home I don't care they're not that big either like I'm a 36b and I just hate them so much

I'm 17