Ouch! I'd stop using the Epiduo for a couple of nights and moisturise, moisturise, moisturise. Then you could maybe try just a very small amount of Epiduo every other night to give your skin a chance to adapt to it. Don't even use the pea size amount to start with, literally just use a tiny amount spread very thinly to see how your skin reacts to it then try ramping it up if everything's going okay. My skin didn't react like this on starting Epiduo but I'd already used benzoyl peroxide a lot before so that's probably why. If it helps, this doesn't look like an allergic reaction to me, just maybe a case of starting too quick. Hope things improve!