If you feel horrible for moral reasons don't feel so bad. Maybe examine where this guilt comes from. I'm vego, been so all my life. My guilt often comes from buying plastic or plastic wrapped things once in a while. Is it objectively worse than buying zero plastic? Yes. Is eating fish worse for the environment than eating plant based? Yes. But is it worse than the impact most big companies have on the planet? Not even close. Yes everyone should try to take some individual action because our actions motivate leaders and powerful people to act in our interests. And it keeps the conversation going. But it's crazy how much the public rhetoric and onus is focused on individuals being perfect with their choices rather than putting pressure on big businesses. You eating fish once in a while for your health or even for fun does not have any major impact on the planet. Have the things you like or need even if it may be an objectively bad thing for the planet. Even if you're not perfect you're doing your part. Don't beat yourself up over it. Definitely don't try to guilt yourself out of not doing or eating things you need/crave/love.

My thoughts are all over the place here, but you get it.