Robbie Williams says he nearly died from mercury poisoning after eating too much fish every night.The singer has resorted to a vegan diet since a routine blood test in 2017 revealed dangerously high levels of mercury in his system, meaning he could have “dropped dead”.“I was eating fish twice a day and I’ve got the highest mercury poisoning the doctor has ever seen,” Williams told Radio X.“Do you know what I thought when I heard that? ‘I’ve won!'” he added.