At the bottom of my gums the pain is like a really bad throbbing pain, I brush my teeth 2 times a day and they are sensitive but what is this?

Need to see dentist. Throbbing pain could be sign of infe tin or abscess..If in gum area so should get it checked..Hard to say without looking..What exactly is going on..See dentist soon before it gets worse.
Infection. Throbbing pain symptom of abscessed tooth. You need to see dentist asap boffo re this gets even worse. Note also that brushing alone does not remove bacteria between the teeth.
Possible Gum Recessi. It is possible that root exposure may be a reason that there is throbbing pain. If these symptoms continue, i suggest a visit to your dentist to evaluate this possibility.