Once you lose your 8 lbs. water weight in the first week, you should settle into losing about 2 pounds a week on your 800 cal a day diet.
This weekly weight loss is fat, so it is real weight loss. It is something to be proud of.
A person uses about 1800 calories a day, so you have a 1000 cal a day or 7000 calorie shortfall every week. A pound of fat is worth 3500 calories, so that 7000 calorie shortfall works out to about 2 pounds. Every week.
I found that I plateaued some weeks, but lost more than 2 pounds other weeks, so it averaged out. If I cheated with some potatoes or bread that would stall me for a few days until my body used it up, and then the weight would start dropping again.
I am a daily weigher and I found I could predict how the weight would move depending on what I ate, even though I was very careful not to exceed the 800 calories. Eating carbs would slow the loss for 2 days, but then I would have a big loss the day after.
Eat lots of vegetables at supper. They fill you up and they don’t have many calories. Today I had cauliflower, squash, broccoli, cabbage, green beans, kale and a bit of leftover carrots along with my pork tenderloin. The beans, squash, cauliflower, and carrots were all sauteed so I also had plenty of olive oil, which helps you feel full for longer. I prepare 5-6 veggies every night. An interesting side effect is my wife gets annoyed cooking this many vegetables, so I have now become the main cook around here (we are both retired) and she just cooks for special occasions. Its a great way to exercise your creativity having to find yet another way to prepare a carrot!
One more thing. Your brain runs on glucose and when you restrict carbs, the brain has to fuel itself with ketones. This will affect your mood. I found that I got seriously sad for a few days starting from about day 5. Then my brain got used to the new reality and I was fine after that. I am now back on the 800 for a few weeks after a holiday and I noticed this again, but it only lasted a day this time. Your bit of a rough patch right now might be part of this.
Good luck. Find an eating plan that you can live with and the weight must come off.
Jan