While veganism is clearly something motivated by some distorted ethics, the arguments for the cessation of large-scale animal agriculture, and especially the meat and dairy industries, are very strong.
Meat is incredibly expensive to produce, and there are a lot of negative externalities associated with its production. In addition, the opportunity costs of meat and dairy production are astronomically high, as we devote over half of our total land resources to these production chains. Around 1/3 of all arable land is devoted specifically to raising crops for animal consumption, for the purposes of providing meat and dairy products that (could feasibly, let alone in practice) feed less than a tenth of the people that crops grown for human consumption on the same land would feed.
World hunger is something we have a solution to, in the present. We just need to stop consuming such large quantities of meat, and in particular, beef. Of course, solving world hunger is hardly the only benefit of ending this destructive, unsustainable practice. The largest source of every kind of pollution - solid, air, and water - is animal agriculture. Human health would of course improve dramatically with the dietary reduction of meat, especially in some of the most costly areas for public health like obesity and diabetes.
The aforementioned land used for ranching and growing crops for animal consumption could be repurposed not only into farmland for human use, but also serve as a perfect place to deploy wind and solar energy collectors.
Whether you agree that climate change is anthropogenic or not, the fact is that most negative greenhouse gasses are produced by animal agriculture; and in places across sub-Saharan Africa and South America, ranching is by far the leading (to the point that it may as well be the
only) cause of deforestation and desertification. Water resources that are essential to human habitation in these regions are being rapidly and primarily depleted by herds of cattle, sheep, and llamas, forcing people to abandon their communities and move to increasingly crowded urban centers. Disease and conflict spread from these crowded slums in the Third World to our major cities, and the problem will; in fact,
is getting worse. In the next five years the UN expects millions of refugees, created by both the climate and conflicts (both primarily driven by animal agriculture), to flood across the Mediterranean and into (Western) Europe.
We can stop this
today - spare ourselves the costs of this catastrophe, and benefit greatly in a wide variety of areas. All that's necessary is a reduction in our meat consumption. There are supplements for all of the nutrients, vitamins, and proteins provided by meat, and there are many different alternatives for its taste.
Of course I don't expect that anything will be done on a national level to address these issues, but you can personally benefit considerably on both a personal and societal level by removing the majority of meat and dairy from your diet.
As much as I understand your desire to have questions answered, I think you can understand my reticence.
If you are unwilling to provide any proof, don't make the claim. No one cares what you have to say about yourself unless your experiences are relevant and verifiable.