The symptoms that you have described suggest that you have acidity and indigestion
with possibility of intestinal infestation. You need to do two things first of all get that lump under your breast examined by a surgeon and get a stool examination. Meanwhile you are doing good in maintaining a good diet but you need to make sure that you indulge in good amount of physical exercise as well. You may visit a doctor who after examination may advice you a good antacid
which will help you a lot.
Please get your breast lump examined by a surgeon
Dont be too concerned though. Wishing you a speedy recovery