hi there! It's NOT gross. You are not gross and should not be ambarrassed or ashamed.
Is it jus that the breast has not grown, or is there an underlying condition? Does your sternum (chest bone) dip inward more than "other" people's?
I have Pectoralis Excavatum, my sternum dips in causing the issue you have described above, even with one nipple slightly inward while the other is where it "should" be. I did not know of this condition until I was 21 years old. I am now 26. I only found out about it because I was also ashamed of my chest and finally decided to have breast augmentation. My surgeon told me what it was. She was amazed no doctor ever told me, and I had had regular physical exams at my gyn office (and even been examined when pregnant with my firs child at 18).
It can certainly be fixed if you want, or to compensate you can buy padded bras and remove the padding from the larger sized one. I went the surgical route, but to be honest even if they were the same size I would have done that to make em bigger. :)
Good luck - and please don't ever feel "gross" !
I'm hearing a lot of support for you, and that your condition may not be all that uncommon.
please note that most of our bodies are not exactly symetrical. There will always be some variation from side to side, and never an exact bilateral symetry.
That being said, I understand how unequal development can make you self-conscious... but as several have said, your breasts may be very appealing to some just as they are.
Certainly, you can speak with your doctor or at your next GYN exam to express your concerns. Perhaps there is something that can be done to heighten development, but as I recall, breast development is not something that can be "Willed".
There used to be a chant in high school that the girls phys ed classes would chant while doing aerobic exercises to develop the chest mussles.
"We must, we must, we must improve our busts..." Now, whether this has actually helped anyone or not, I don't know... but it leads me to think that there are some exercises that a woman can do to improve mussle tone, lift and support.
As for differences in nipples, tone or size, I doubt there is much that can be done. And frankly, I won't worry about that.
A man that judges you solely on the color or tone of your nipple is not worth worrying about. A real man will be attracted to your personality.
If you love yourself, it will show through.