You do realize that HBP and cholestrol are affected by genetics, desserts, exercise, and many other factors, so random anecdotes like "I know a girl" aren't very helpful?
Americans on average eat 55 pounds of beef a year (the 4th highest total in the entire world, just slightly trailing a few Latin countries), and Americans have the world's highest obesity rate outside of tiny island nations. So if we're just using random correlations as an argument then your case looks pretty bad.
Sources of greenhouse gas emissions, inculding electricity production, tranportation, industry, agriculture, and forestry.
www.epa.gov
agriculture, including meat production, only accounts for 11% of our greenhouse emissions, and people are always gonna eat food. It would be more realistic from an environmentalist perspective to focus on reducing the other 89% of our souces of greenhouse gas emissions.
Mass transit imo is one solution. Because both gas cars and electrics both produce a high percentage of our emissions. Mass transit would help reduce the two leading factors in a way that is actually more convenient for the average person. (ie my strategy is to find solutions people will like living with because people unfortunately like luxury)
another good palatable way for the average person i think would be to step away from gas and electric power in homes, and try to go solar. People wouldn't be bothered by using solar power either. (my entire shed is powered by solar energy for example, hoping to get the main house that way eventually too.)
Encouraging businesses to do this too, would also be great.
A much more viable strategy than the impossible "make everyone vegan" approach. which will 1) never happen, and 2) do little to reduce emissions even if it did.