I have a hard ball like lump on the lip area of my vagina. Its sore to the touch and itchy a bit. Kind of looks like a pimple. What on earth could it?

Sounds like a cyst. From the description you gave it sounds like a cyst. They can be very hard because they sometimes have calcium in them. I definitely recommend you see a gyn or a dermatologist to confirm the diagnosis and they can discuss with you removing it.
Many things . There4 are several possibilities and an examination will be needed to determine the cause and treatment. Possibilities include a pimple, a hair follicle, a cyst, herpes outbreak, a wart, small infection and others.