Basic tip to get started: make a list of small, sustainable changes you will commit to trying for 1 week. Just 1 week. At the end of the week, look at your data (weight, inches, energy levels, etc. whatever output you have) and evaluate how the week went.
Then repeat. Add more changes, tweak some changes, throw out some changes that didn’t work for you, etc.
Take it slow and ease into a healthier lifestyle. Good luck!
This is just a different discipline, but you can do it. The buy-in is rough, especially if you also eliminate a whole bunch of stuff right at the start, but it’s not impossible.
If you think it might be dairy, that goes away really easily anymore, except with regard to cheese. Vegan cheese is not it. But oat milk is good and cashew yogurt is really good and there’s even pretty OK vegan ice creams (that will test your discipline). But cheese is tough.
So you may start with just eliminating lactose, which leaves you butter and aged cheeses like cheddar and parmesan.
If you try to cut all fruits, that’s a job in and itself. .
If you take away gluten, and then reintroduce gluten, your body maybe will get mad at your and pretend not to tolerate gluten. But you can get re-tolerant to gluten.
So just watch your calories and don’t get too austere in the very very beginning. It’s a little easier to clamp down in stages. Right off, no potato chips and no red wine and you’re already eliminated plenty-o-calories right off.
Good luck