You were fatigued because you were not eating enough ffood to meet your caloric requirement -- you are seriously undereating at that level. You removed some of the severity of undereating by eating those carbs.
I understand why you fear gaining weight as a recovering anorexic. I also understand the OCD component. It may be helpful to you to ask people you trust about how you look because you cannot trust what you see in the mirror. Your brain lies to you, and it beats you up.
The truth is your body is not getting what it needs at 1000 calories per day. It is also true that if you eat sufficient fat and protein you may gain weight, because your body may try to restore lost muscle mass and the lost fat that is necessary for a grown woman to have for good health. Further, your body my be designed to carry more than the 125 pounds you have on your 5'8" frame, and gaining weight will make you healthier.
I suggest you try limiting your carbs to 40 - 60 g net, and set a calorie goal of 1400 per day. That is a very low goal, and I know it may seem monstrously high given what you've eaten in the past. If you can't make yourself go that high, shoot for 1200. This is part of recovery, it is not optimal. Optimal is more likely 1800 calories or more.
The minimum amount of calories your body requires everyday just to survive, without movement (i.e. spending all day in bed) is your Basal Metabolic Rate. You can calculate yours
here. I guessed your age at 25, and came up with 1400 calories. When you eat less than that your body is stressed, and must use fat reserves. You do not have much at all for fat reserves, so you experience extreme fatigue. Note that the 1400 calories is just to live, breath and have your organs function. It does not include the calories necessary for you to walk around, shop, shower or do normal life functions.
I hope that you are getting help during your recovery and not winging it alone. You are very courageous for posting about this topic, and it must be one hell of a struggle to overcome anorexia. Congratulations on taking steps for recovery -- anorexia is an utterly cruel disease. I hope you are feeling better soon.