Wow - interesting (and speedy) reaction to changing your diet! There was a very good programme on tv about veganism, presented by a premier league footballer (can't remember his name or th club), he talked to footballers at Forest Green Rovers, a vegan club. Apparently, they noticed feeling better after a meat-free day, and now, with a vegan diet, they experience fewer injuries.

I like my cup of tea, too, and butter 😎, but I've eaten very little meat for months, for preference rather than anything else, and my cholesterol reading has dropped so low I thought it was a mistake!

There's some good recipes for non-meat shepherd's pie, is your mum up for experimenting?
Jamie Oliver Allotment Pie and
Hairy Bikers Chestnut and Mushroom Pie