Diets don't work you need to make a lifestyle changes and it will take some hard work, honesty, determination and perseverance on you behalf. It will also require buy in from those that live with you.
The first thing i would suggest is to eat as you normally do now but keep a diary of every thing that you eat and drink for two weeks, be specific and honest eg egg and bacon sarnie ie whats in it- white bread, butter, fried egg x3 bacon slices bbq sauce etc or you pop into the hair dresses and pick up a sweet from the bowl on the counter that gets recorded. Any thing that gets ingested gets recorded.
After two weeks transfer all that information onto a large sheet of paper (or an excel spread sheet) in to groups eg breads, spreads, veg fruits , then review and see what can be eliminated eg opportunistic snacking eg the sweet from the bow at the hairdresser, what can be substituted eg a banana for the morning tea doughnut , carrot sticks and hummus dip for the afternoon bar of chocolate. Also review what healthy substitutions can be made at meal times ie brown bread instead of white, oats muesli or porridge for corn flakes. grains pulses instead potatoes/ pasta or whole grain pasta instead of white pasta etc. greek yougurt for full fat cream.
Fruit veggies and salad must become your new best friends.
Once you have that sorted do a weekly meal plan and shopping list, which you need to stick to. When planning the meals aim for two meat, two, chicken, two fish and a vegetarian for the main meals each week, plan to have some left overs that can be taken for lunch the next day with a large salad. When making the main meal see if you can sneak in extra veggies eg add cauliflower to a chicken curry.
There are loads of recipe web sites that can offer easy, tasty & healthy options which once you get used to you can adjust to suit your own taste, don't be afraid of herbs, spices, lemon & lime juice for flavour.
When shopping use the nutritional panel to compare similar food items using the following guide livelighter.com.au/Assets/resource/wallet-card/LL-STAR-rating2.jpg
Get plates that are no more than 25cm wide and watch you portion size aim to have at least half the plate filled with veg three, a quarter with the carbs and the remaining quarter with the protein . eg chicken curry as above, basmati/brown rice, broccoli, carrots, pumpkin. My reward for eating the most of veggies first is to get the carbs and protiens
Aim to have three to four pieces of fruit per day. I prepare and have x2-3 different fruits on the table for after the diner eg 1/2 apple 1/2 mandarin 1/2 banana. Knowing that these too have to eaten stops me over eating or going back for seconds.
Drink lots of water and watch the alcohol intake. If you take sugar in tea/coffee try a gradual reduction to none or use a sweetner
Be kind to your self if you like some thing sweet have it ... but just a little bit eg 1/2 the kit kat rather than a whole one. One plain choccy biscuit and a rich tea than three choccy ones.
Get your self a cheap pedometer and aim for 10,000 steps per day, if your fairly sedentary now work up to the 10000 over a period of about a month.
Get the Micheal Mosley book The Eight Blood Sugar diet and read it for inspiration and advice ... use it to give yourself a foundation for making the life style changes.
Before you start see you GP to have you blood tested and get a blood pressure measurement. Record you weight and you waist measurement, hide the results in a safe place and then forget about them. You will notice the changes in the size of you clothes and how you begin to feel in yourself. After 6-12 months go back the GP for repeat blood tests and re measure and weight yourself and compare to those ones that your hid in the safe place. You'll be very surprised and pleased with the results.
This will be a process and it will take time and there will be days when you eat the whole packet of biscuits or you go on a night out and have a big feed. Don't beat yourself of feel guilty about it .... remember tomorrow is another day and if you stick to your meal plan for the rest of that week it wont make that much difference.