Physical Pain, as an adult, withdrawals from Effexor without a doubt. Childbirth was nothing compared to that because at least there was an end to it.
Withdrawal pain from Effexor didn't stop, there was no way of escaping it whatsoever. (except to take more Effexor which I ultimately had to do) It takes a toll physiclly & mentally you go on a brain zap, emotional roller coaster. Kinda like trying to ski downhill on ice. It knocks the foundation of your thinking/ coping out of wack.