You misunderstood the science. Not getting a sufficient intake of nutrients, including proteins, is what's killing you. You can easily get proteins from plants and plant based foods. Then everything is fine.

but we do have to because we evolved to require it over 12k years ago and nature is cruel like that [...] consuming flesh is inevitable

No. We didn't and we don't. If I am not mistaken, in humanities history we mainly had a plant based diet. The massive increase in meat consumption is a rather modern phenomenon.

We are omnivores, yes. That means we have a digestive system which is able to process meat as well as plants. But that doesn't mean we have to use both or a single source. It is possible to get all of your required nutrients from plants and plant based sources.