To add to what engineer said, daily weight can fluctuate by a good 7 pounds. That's due to water and salt, mainly. The big weight loss push that we all get at the beginning of a weight loss plan is generally due to a loss in water weight.
What do you typically eat in a morning? Fer reals, this is what I'm eating (right now, in front of the computer, which I should really stop doing, but
I've got schoolwork due) - an omelet made with egg beaters equalling 2 eggs. 3 oz of salmon cooked with the eggs (this is salmon, not lox, and so it is a lot less salt), about 1/4 c. of onions, broccoli and peas mixed together, about 1 oz shiitake mushrooms. All of that was mixed together and cooked in a T of coconut oil (usually I use just the spray but today I'm going for the oil as a change ). No salt. Dash of dill added. Side of various fruits - it was what we had on hand, strawberries, blueberries, blackberries and some enormous red grapes. Probably about 1/2 c. of the fruit, which is all fresh.
I am also eating all of this with chopsticks which makes me eat slower. I'm washing it down with a 32 oz thermos of water mixed with unsweetened decaf tea. I put in some stevia because otherwise it's kind of icky.
I drink 12 eight oz glasses of water/weak decaf tea/day. Most diets recommend only 8, but more is better on higher protein days, like I'm having today.
You'll notice that nearly nothing in my breakfast (which is huge, I might add, and is around 450 - 500 calories or so) is what anyone would call 'diet food'. I eat egg beaters because I like them and on my father's side I've inherited a tendency to have elevated cholesterol. Stevia is sweet but it's natural - toss your standard artificial sweeteners. Most of them are really bad for you, and they can make you crave regular sugar even more.
Tomorrow, breakfast will be instant Scottish steel-cut oats. Changing up your food is helpful. It makes everything more interesting, so you're more likely to stick with your improved eating habits, you're more likely to get the nutrients you need, plus changing things up seems to make it more likely for you to lose.
May I ask how old you are? Do you live alone? Dieting can be difficult if everyone else in your home is on a different page than you are. My husband isn't looking to lose weight, but he will eat with me when it's dinnertime. Otherwise, we're both on our own (it's just the two of us). Most of what he eats as a junk food 'treat' he does so outside of the home, like he might have lunch out while at work and I just shrug. I'm not there with him during the day so he does whatever.
I know that eating more feels counterintuitive. This is why I am suggesting your doctor plus a referral to a nutritionist (or dietician; the roles are similar but dieticians are more regulated in the US). This person can help you to put together meals that work within your time, your budget, your cooking skill level, your preferences, and your need to lose weight. And a workup at the Y or with a personal trainer (I am suggesting the Y as they have trainers and are a ton less expensive than private gyms) is a good idea because they can help you with proper form and how to best work within your size, your strength level, your interests, etc. Plus they can help to keep you from getting injured.
Pulling for ya!