High risk and have an odd dot on my right breast?

A painful spot on the skin of the breast is not usually a sign of breast cancer. If this is your only symptom, then it sounds more like a rash or something related to the skin.  Personally I'd give it a few days to see if it starts to resolve on it's own.  If not, then I'd see my doctor and if he didn't know what it was, I'd ask for a referral to a dermatologist.

Your grandmother having had breast cancer most likely does not make you high risk. 1 out of every 8 women develop breast cancer so it's pretty common to find some relative somewhere in the family who's had breast cancer.  Most cases of breast cancer - 85% to 90 - are not genetic.  The primary genetic mutations that cause breast cancer do not skip a generation - if by chance your grandmother did have the genetic mutation and did not pass it along to your mother or father (whoever her child is), then you cannot have inherited it.  Of course not everyone who gets the mutation does develop cancer, but the risk is very high and in most cases where the mutation is in the family, there are multiple cases of breast cancer, ovarian cancer, prostate cancer, etc. across several generations.  Do any of your first degree relatives (parents, siblings) have any of these cancers?  Or have a number of second or third degree relatives (grandparents, aunts, uncles, cousins) been diagnosed?