Moving Away from Veganism

I often feel like I'm living in a state of being "one supplement away" from curing my deficiencies. 

Iodine, zinc, B12, selenium, algae DHA, ALA, vitamin D, protein powder, B complex, probiotics, etc. 

To be honest, I'm getting tired of endlessly researching and buying expensive supplements. And then when I take the supplements, I'm still not feeling as good as when I have a piece of salmon or an egg.

There's something that I'm missing, and I don't know what it is. And I'm a smart guy. I've done endless research. 

Yes, I'm venting here. Not throwing in the towel. But also... I'm not committing to anything either except a journey towards optimal health.