i have been having those pains to in my right breast i had a lump removed from that breast a few years ago now,(only a blocked milk duct thanks goodness) i have been massaging mine like you have been and seems to be helping a bit,i also find that having a warm face cloth over the sore spot helps a bit to not hot just a warm one and when massaging not to push to hard.
I hope this helps and you find something to help you soon.