My poor camellia plant.. looks like it is spreading to the nearby one as well.

You just need you some ladybugs, green lacewings, hoverflies, etc...!

You will need to wait until the shrub replaces some of those leaves, although you could remove the worst ones if it bothers you much. Just checking... is your camellia getting consistent watering & afternoon shade, say, from 11am and on, during the summer months?

looks more like tea scale to me. horticultural oils are generally recommended although blakrab's recommendations for predators are also relevant options.. read instructions carefully before using pesticides as you can harm the plant if applied inmproperly or at the wrong time.

Jeff is correct. Male and female tea scale, a very common pest of camellia. Anyone who has camellia plants needs to recognize the yellow splotches on the top and the white (male) and black flecks.

Horticultural oils need to be applied to the underside of the foliage. Read and follow the directions on the product of your choice.