From the other perspective, I was vegan for four years.
It wrecked my periods, they changed from being painful & needing ibuprofen to being agonisingly stomped on and no painkillers would touch the sides.
It wrecked my mental health, I was a regular vegetarian in my late teens and early 20's. I suffered then terribly with crippling social anxiety and depression (massively underachieved at college and university due to non existent motivation and energy). I didn't eat junk food as such, but did eat things like home cooked pasta and sauce dishes, vegetables in curry sauce and rice etc. Likewise in my vegan period I ate home cooked meals, basically beige carbs, tinned legumes and supermarket vegetables. I became so reclusive and phobic of even answering my phone or reading emails, and suffered brain fog so I couldn't concentrate on anything. I felt dull, flat and apathetic all the time.
I then read a book called the Vegetarian Myth, where the author suffered many health complaints such a crumbling spine, digestive complaints, depression etc. It was an epiphany moment, and it goes into the ethical and ecological aspects of vegan diets and how farming monocrop plants like grains and legumes have a far bigger impact on animals and wildlife than eating pastured meat, and that large amounts of carbon in the atmosphere can be sequestered into the soil if we convert croplands into pastured rangelands. The plough, the combine harvester, the cropdusters, the rodenticides around granaries kill trillions of animals and insects per year and destroys the soil structure, and the carbon absorbing potential of humus, so that we've only got a few decades of harvests left of grains. Even growing lettuce in your own garden requires an armoury of all kinds of -CIDES. Whereas one pastured cow can feed one meat eater per annum... and that is the path of causing least death to animals and sequesters the most carbon.
I've been keto/primal-ish for a while now and I feel that I'm finally in recovery from my diet. I can participate in events, keep in contact with friends, use social media and keep on top of chores better. I eat local beef and lamb from the butchers in town (5 mile radius), local/UK grown vegetables, sauerkraut/kimchi, raw milk, kefir, eggs, dairy, the odd sliced potato on a hotpot but otherwise minimal carbs.
There's many nutrients that are minimal or absent in a vegan diet:
B12
K2
D3
DHA
The retinol form of vitamin A (many people have a genetic polymorphism where they cannot convert betacarotene in veg to retinol)
Taurine
Carnosine
Creatine etc etc
K2 is especially important, it helps shepherd calcium away from the arteries and soft tissue where it causes vascular disease and into the bones and teeth. It's why many vegans suffer from bone loss/weakness and tooth decay. I urge vegans to at least eat a fermented Japanese food called natto or take natto based supplements.