Wow. There is a half way house though mate. Just eat stuff you are confident you know the provenance of - I have done that for years. My Christmas day Turkey from Gartmorn Farm near Alloa was eyewateringly expensive but I am confident that the ugly birds had a fantastic life frolicking in their woodland and pastures, having as close as a natural life as it is possible to have and were slaughtered humanely. Likewise all the meat, poultry, game and fish I buy and eat.
If you are determined, you need to keep off the fish then as if they are wild they will be hauled out the ocean and left to suffocate slowly. If farmed, well its too close to lunch to go into gory detail...
Good luck whatever you choose but my view is that life is too short to deny yourself one of the great natural pleasures.