Well why on earth are you setting up expectations for an output you cannot control? You can't make your body lose weight at a fast or steady rate except inasmuch as your eating and activity supports an energy deficit - day after day and month after month.
Four pounds in a month is healthy and VERY average for a woman. And if you're truly eating, every day, exactly 1000 calories along with your workout, you're under fueling you body and could be thwarting your progress in the gym because of it. Another serving of protein might do you a lot of good for properly fueling the workout and recovery cycle.
But truly, your frustration is because of your expectations, NOT your body. Your body IS losing and has lost significant weight. But because it isn't doing it in your preferred speed or timeline you're considering it a disappointment or failure? The logical thing to do is reframe your expectations. If you get in a nutritious day of on-plan calories and your daily workout, you've succeeded. You've won. You're awesome. And the scale and tape measure will do what they will do. You can't control them, so why base your contentment and happiness on something you have no direct control over?
Celebrate your achievements in adherence to your plan and give up counting on the rest. If you are consistent day after day and year after year, you WILL be healthier and WILL move closer to your goal, if not reach of exceed it. But this timeline and rate of weight loss you have in your head is nonsense, and it is defeating you mentally for no good reason at all.
And there's the tough love. Get over it and get real, you're doing just fine if you account of calories and exercise is accurate