I agree you should know you've flared up so suddenly. Acne can show up due to various reasons such as stress, hormone inbalance or allergies.
If it's hormone inbalance, then you'll need antibiotics. However, I agree with previous posters that mentioned Roaccutane (Accutane for US citizens) should be the very last thing tried. I was on that thing when I was young because the dermatologist said so but the family doctor listed all the side effects, which prompt my parents to panic, ignore the dermatologist (and the money they had spent already) and just ask for another thing altogether. So the doctor put me on a special type of pill for acne. It is called Diane 35, popular in Europe, but not so in the US and Canada (I don't think it's even sold there) but you can ask for similar products anyway. It has side effects too. The most troublesome was the blood clot one, but I was on blood thiners too (some insufficient blood circulation), this isn't a problem for me at least. I did get fatter though.
I'm also on Avène's Cleanance line for three months (no Diane-35) and I must say it works too! Especially that Cleanance K thing. I'm not sure about the TriAcnéal (?) but I'm actually going to buy it tommorrow after seeing some reviews online to take care of menstrual break-outs. However, these things are very personal. I've found out I should not use the toner very often, because my pores are already quite tight as it is and the moisturiser / sunscreen doesn't penetrate the skin if I use it, leaving a gross film instead. However, there are people that defend the use of a toner to take all the oil. It works for them, but not for me. You should take this into consideration when seeing raving reviews about something but then trying it yourself and getting worse.