hi, thank-you for the brief history of you. as you mentioned you have pain in the armpit. Such pain arises if you have slept in any abnormal position or also if you have any respiratory pathology. Since you haven t mentioned anything about getting trouble while breathing and also you didn t mention about the cough , we can rule out this one thing of Respiratory issue. now coming to the next is, there may be chances of you compressing that area without your knowledge. it can occur in sleep or even while wearing tight clothes. Now since you even added that there is a swollen lumps of the breast than it is good if you get your breast examined by your gynec. as certain times the swelling is due to the obstruction of the limb nodes or may be excessive secretion of the glands. you can even take the x-ray of the painful area which will help us to rule out any of the fracture or lung related issue. You can even look on a later to under go myelogram to find the abnormality of the glands. post which we can come to any symotomatic support through medical. I hope you will understand this and will be able to get the test done which will help us rule out the possible different diagnosis. With the grace of God I Wish you a speedy recovery regards