What youre describing could be cystic acne, the lumps under the skin. You really should go to the dermatologist. They have some pretty good treatments and can properly diagnose the lumps.. and treat it all. There are all kinds of "acne" and reasons for it. If you can, get your parent(s) to get you to a dermatologist asap.
I really wish you werent so self conscious and didnt feel so bad about it. I understand why, but its just sad to hear youre going through this. My oldest daughter had a rough time with acne and other kids are just too rotten sometimes. Her dermatologist helped her out with a regimen of skin care, rx body wash for her body acne, and topical antibiotics along with pills. She didnt have to stay on the pills, but she does have to keep up her beauty regimen. It was never what you would call "perfect" but it did help tremendously and her self esteem was much much better.
Hang in there kiddo.. and much luck to you! Check out the acne board here and remember : just because someone else has a horror story or something didnt work for them, it doesnt mean it wont work for you. We are all different.. and not one of us is perfect!