Quick update: I only seem to feel the pain in my underarm/breast area when I am sitting at my computer. When I am standing with my arms at my sides, or if I sit up straight at my computer, I feel the ache less. I still have the arm pain/muscle tiredness however.
I have been getting what feels like heartburn recently, since Sunday night. It comes daily between 2 and 4 pm and I don't start noticing it going away until about 10pm to midnight when I go to bed. I haven't been eating properly, and usually if I eat ANYTHING, it's mozzarella string cheese, peanut butter (1 tbsp), an english muffin with cream cheese, or Organic Vitamin D enriched whole milk, to name a few examples.
I also have been seeing a number of zits/ingrown hairs coming up on both my breasts, but they appear on the underside of my right breast (I have about 5 total there) and on the top of my left (There's about four). I don't know if that's related or not.