If you are in pain why would you bother with a cwe? All that does is remove the acetaminophen which will definitely help relieve pain. Cwe is for people who need high doses to feel it, and chronic pain patients worried about their liver. You should be fine without it. Just remember no more than 4 grams (4000 mg) of acetaminophen in a 24 hour period, and no more than 1000 in a single dose. (Hour in between should suffice)
I've never had any acetaminophen related issues but be weary if you have pre existing liver troubles as symptoms don't present themselves for 12-24 hours after the damaging dose is taken.