Advice? OK, the best advice is to plan ahead.
Write out a menu plan for the week. Breakfast, lunch, dinner and a treat once a week, only. Plan filling nutritional meals that you enjoy. There are plenty of great fresh soups in cartons (avoid tinned or packet) these days, that's lunch sorted.
And I think you're going to have to bite the bullet and start cooking from scratch.
When you get an attack of the 'munchies' wait 30 minutes and use the time to go online and find tasty meals.
Finally you don't have to lose lots of pounds every week. A regular loss of 1lb a week is best. And get moving. Walk, swim, whatever suits your lifestyle.
New house and a sloping garden
How do you acknowledge Easter.