Eating Bad Fish. How do you describe a "Bad fish"?

[DollyDarling]

I was a vegatarian for years and for the last 4 months have added fish to my diet. Most of the time it feels right in me and I am happy then to eat it, but occasionally something doesnt seem right. Like tonight. I ordered salmon and it was very chewy and looked hardly cooked so i said to waiter "its bad please cook more". They brought it back out very cooked and still chewy. I ate a tiny bit and then said "take it away its disgusting". Im feeling very ill now and I didnt feel this way before I ate it. So Im not sure if it was bad or not. They insisted its not bad and made me pay for it tho I didnt eat it. Id like to not have this delemna ever again. How do you tell if the fish is good or bad, cooked enough or not enough? I did ask my Italian client tonight who works in a restaurant, and I said "but the japanese eat it almost raw and its ok" where he said "yes but its super fresh, like just out of ocean when they eat this way. You cant freeze a fish and then eat it raw like that, it must be cooked after being frozen." I didnt know this before he told me. Any other pointers I should know about? I am going to try cooking my own fish since I cant get it prepared right by others it seems. Any advice on this? Knowing if fish is bad or ok, ect?

Im hoping to find some really good restaurants in Ireland with very fresh caught fish. I love Salmon. Any recommendations?