I'll keep this simple as it doesn't need to be complicated as so many fitness and exercise blogs make out.

You don't need to exercise but any exercise you do will help you mentally and physically and shall await the weight loss. Go slowly - do not injure yourself.

Eat approx 1700 kcal of lean meat, vegetables and fruit a day. Count your calories. Stop eating processed food and sugar and snacks. Your go to snack food is now an apple, banana or handful of nuts. Soups are great for feeling full. Drink water. Lots of water. It'll keep you feeling full.

Do not have "cheat days" - eating extra food on a Sunday for example.

Quit alcohol and smoking.

You'll lose approximately 1 or 2 lbs a week if you stick for the above. Calculate your desired weight and reach it. You'll look loads better in 6 months and then in a year.

Keeping a diary of progress and photographing yourself can help keep motivation up.