Sorry i didn't see this earlier for a few reasons. For one thing, painful lumps tend to not be what you were fearing it to be.
But just one important thing to note, since it was brought up.
Breast cancer is now 97% survivable. That is indeed remarkable.
But of course you have to get yourself to a doctor in order to be treated. One of the worst possible responses is for a woman to be terrified into inaction, when action will save your life.
When you have something like this, get yourself to a doctor and get it checked out pronto. More than likely it will be nothing. But if it's something, it is NOT a death sentence. Far from it in fact. But treatment of some sort will be required. The sooner the better.