I’ve done lots of small things over a long time, which together have made quite a difference.
I’ve cut down carbs and eat lots more veg. I take food to work or with me on a long journey , to avoid being tempted by carby snacks.
I only drink water and herbal tea.
I’ve cut down on alcohol from a few glasses every night to one at the weekend or if I’m out for a meal or on holiday. . TBH I’m out of the habit of drinking at home now.
I watch much less tv, about 2 hours a week. And read more .
I’ve cut some toxic people out my life. Two I had to go N.C. with, the others I just let drift . Once I got over the FOG, this has made the biggest difference to my well being. A lot of my drinking etc was self medicating to deal with how crap they made me feel.
I’ve stopped reading newspapers or watching the news, because it just made me anxious and depressed about things I can’t change . I still listen to the radio so I still know enough about current events to vote or write to my MP.
I don’t talk about Brexit.
I don’t do Facebook. Like you OP I’m on a group , so I set up a whole new profile for that and deleted my old one. I just read the notifications for that group and check in if I need to.
I’ve stopped shopping as a leisure activity, I only go to buy things I need. Because it just depressed me - I hate 90% of clothes I see, I feel like a freak and old as nothing suits me. I have cut my clothes bill in half, I have more ££ to spend without guilt when I do find something I like. And I still have a wardrobe full of perfectly nice clothes.
With all this free time I have joined two choirs, done an evening class, started volunteering and spending more time gardening ( which is my favourite hobby not a chore) .
I’ve also done C25K, then parkrun and done a few 10ks and half marathons, although I’ve let it slip a bit over the winter.