Unhealthy lifestyle but can't change

Forget the stuff that you know isn't gonna happen in a month of Sundays, like getting up at 6am for a run or going to the gym instead of watching Netflix, and do some easier things first. Rather than start taking away from your diet, instead add in. So research the best foods to eat for energy, immunity, gut health, skin, whatever and eat them every day. At first, as well as your usual meals. So alongside that cereal bar, a bowl of berries. Before you start your sandwich, force yourself to eat a mumsnet massive salad. For dinner, cook up some veg or make a veg soup and don't allow yourself your carby dinner until you've eaten it. 5-8 fruit and veg every single day. And no gin until you've drunk water/green tea.

At first you'll think, I'm taking in even more calories here! But you will find that the good healthy stuff means you'll have less appetite for the unhealthy foods and will also make you feel better because you're getting the right nutrients. After you've mastered that, then the time to start gradually swapping out the unhealthy for even more healthy foods. It worked wonders for me.

buy more veg. easy veg like broccoli or frozen peas or frozen sweetcorn is fine - it doesn't have to be hard work to cook. even baked beans are OK.

cook smaller portions of your pasta / potato etc and do a portion of veg too.

also, get some slightly smaller plates and serve the food just in the middle (like a posh restaurant) and you'll find you eat less.

Pick one thing and start there. If you are in a rut and lack motivation you’ll keep setting yourself up to fail.

how about breakfast? Why not challenge yourself to have a nutritious breakfast for a month and get DH on board. Porridge or boiled egg is easy. Swap the cereal bars for those on your next shop.

if you can do that, move on to something else for the following month. Maybe switching the takeaway from once a week until once per month? Then

You need to make one small change at a time. Once that becomes habit introduce another change.
Start small, but stick to it.