You've gotten a lot of good advice, please speak w a doctor.
Also consider the "eat half of each meal twice" approach - Suppose your ordinary breakfast is a cup of coffee, a banana, two whole grain waffles and a yogurt cup, and you eat it at 9 am. Drink 1/2 a cup of coffee, 1/2 a banana, 1 waffle, and 1/2 yogurt cup at 8:30. If you are famished, have half a cup of berries, an unsweetened fruit salad, a handful of grapes, etc, and a cup of water or a cup of unsweetened tea. at 10:30, you can eat the second half of breakfast (if you can manage), and again bulk it out with the healthy low cal foods/ beverages.
same strategy with lunch and dinner. you will be eating only half of your usual serving at a given seating. you can bulk each out with additional non processed fruit vegetables, broths, beverages.
Slowly but surely, you will find yourself wanting less and less of the 2nd half of the meal. Unable to eat it (because your stomach capacity has shrunk, and because you are full of other healthy low cal items). What could be nicer than dieting, and finding yourself overwhelmed by the amount of food.
Give up the second half as/ when you are ready, continue to bulk out with the healthy food items.
Do realize, the healthy food items are caloric too. Too many calories, whether healthy, or otherwise, will ultimately have you gaining.
Good luck to you and yours,
F. B.