I would see a doctor, lumps in the area you mentioned could be a sign of something more serious. I know it cost a lot to go, but, it could be cheaper than a stay in the hospital due to something serious.
Do you wear aerosol deoderant? This happened to me once, went to Dr., he asked if I used aerosol, I stopped using it and it cleared up.
It sounds like you have a problem with your lymph nodes. This could be an allergic reaction to the type of deodorant you wear, or something more serious. You should probably be checked out by a doctor to be safe. Under-wire bras would not cause this problem.
be careful b/c u have lymph nodes it that region and if they are inflammed it could be a sign of more serious issues. on the other hand if these lumps are more like boils you may have HS