Bought some inexpensive salmon.. woke up feeling weird?

Ok I know I shouldn't have bought the inexpensive salmon... but it was at cub foods which i haven't gotten bad stuff from before. So next time I will go somewhere else for salmon... HOWEVER we eat it and it was just ok not the best quality... and we woke up feeling really grogy, feeling almost drugged. After a shower I felt a little better but I just feel all over tired when I swear I got a good nights sleep. My boyfriend feels the same way except he didn't feel better after a shower he still about 19 hrs later still feels out of it. Could there have been a higher amount of mercury in the cheap salmon? What can he do to feel better if that is the case? We have tickets for lion king tonight :) that he have been waiting to go to for sooo long and it will suck if he still feels like this during the show. Any tips will be great :)