I was vegetarian for most of my young life, and was vegan for a good 10 years.
I decided to start eating meat when I was in my early 30s, after being convinced that eating meat was healthier. I had never imagined myself being in this position, because I had been such an animal rights activist all my life that I was certain that even if eating meat was healthier, that I would just never do it for ethical reasons.
But as I got older, the health implications won out. I began to eat meat.
The first thing my then husband bought home for me to make was a whole fish. Head, eyes and all. I could have died. I couldn't cut it up, and then after he cut it up and cooked it I couldn't stomach eating it.
I then started off with stuff that was already cut up, like chicken pieces and minced meat - basically so I couldn't recognise that it had ever been an animal. I used small quantities until I got used to it. The hardest thing to get used to was the very different feel of the fat content of soups and stew and things like that, that had been made with meat. The fatty feel just felt so different to things that had only been cooked with vegetable fats.
Honestly, it was difficult to get used to, and a very emotional time. I'd sob over my cooking, and bawl my eyes out over dinner.
And also the mess! Oh the mess of cooking with meat. It splatters and spreads droplets of fat like nothing in the vegetable kingdom! This took ages to get used to, just the mere fact of so much fat splatter and so much cleaning.
I also didn't know how to cook meat. So I had to get ideas and recipes and get things sorted in my head. Dinners were a real trial and bother until I just learnt to cook naturally, eventually, with meat.
Now I'm okay. And I'm very convinced of the health benefits of a diet including meat over a pure vegetarian diet. I'd never go back. And everything is easy now. But is was truly hard in the beginning, because it is changing your whole way of life and entire way of thinking.
Good luck with whatever you decide to do.