Cramping in muscles under breast

[faithful-summer.livejournal.com]

I don't know why I never thought to ask this here before, but I think it's within the realm of this community. I am a 31 year old cis-female, would probably classify myself as very overweight, and have very large breasts. When I was a normal weight, they were I think a C cup, but due to a lot of weight gain (around 100 pounds), I think I am now a DD. I generally wear sports bras at work due to the physical labor aspect of my job, however I should note that I have experienced this problem while wearing other types of bras as well (regular with underwire).

Something that has been going on for the last few years for me is that very frequently when I bend over, I will get severe, cramping-like pain under (either) one of my breasts. Like, right where the bottom of the breast meets the ribs. I really feel like it specifically has something to do with bending over and the angle and body position, but I can't pinpoint it any better than that. Describing it as a "cramp" is the best thing I can think of, kind of like a leg cramp... as much as chest muscles can cramp. But really, what it feels like is that some tissue right under my breast is like, doing the opposite of prolapsing... like, inward lapsing in my rib cage. I realize this description probably doesn't make any sense, but that's what my brain thinks it feels like.

When this happens, I have to straighten up immediately and even sometimes stretch myself backwards and arch my back before it subsides. What I'm really inclined to do when it happens is push upward on the affected breast from underneath, but I have never tried that as this usually happens at the most inopportune times in front of coworkers and clients. In fact, there are some times that I am not even able to straighten up to try to stretch out the cramp because we are doing some work that requires me not to move, and it's terrible.

I never experienced pain like this until the last few years and it seems very directly related to my weight gain/increase in breast size, though like I said, I can't pinpoint exactly what causes it. Many times I bend over, nothing happens. But then sometimes I get that pain/cramp and it's horrible. Has anyone else ever experienced something like this? Short of never bending down, is there something I can do to prevent this from happening? Could this possibly be related to something other than my weight/size increase? Thanks in advance!