Severe cold sore!

So I've always suffered from cold sores..and they are the worst things ever. Ugly and painful! And not to mention, the lengths you've got to go to, to help stay clean so you don't spread the bastard! I havent had one since october 2015. And sure enough I woke this morning and felt my lip and got so angry 😡 but guys, this thing has swelled up like a BALLOON and it seriously looks like ive had lip injections in my top lip. This thing is fucking massive it takes up the entire space of my top right hand side of my lip :( I wanna know when is not normal and to seek medical advice? Ive had them all my life so I know how they work. But this looks so nasty and its so painful :(