Vegetarian eating Fish…?

I am a vegetarian and I had Tuna a few months ago, and I haven’t had any type of fish since – I really like Fish I just feel so guilty because I know that they get killed like the Animals what should I do because I know they are a good source of zinc and Apparently a lack of Zinc leaves white spots on your finger nails and I have got some, How can I work Fish into my diet and not feel guilty about eating it?

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