Hello! As an ex-anorexic and someone who also currently has an atypical eating disorder, I may be able to give you a little input on this. I struggled with anorexia for almost 12 years, and it landed me in the hospital more than once. I currently suffer from a phobia of food induced anaphylaxis, and struggle to maintain a healthy weight due to my severely restricted diet (I am afraid I'll be allergic to almost everything). I am currently receiving psychiatric treatment for my condition, and I recommend you do the same.
I can tell you that the only time you would have to worry about refeeding syndrome, from what I understand, is when you are hospitalized for malnourishment and attempts are made to artificially refeed you, the patient via the delivery of glucose, either enterally (by way of your intestines) or parenterally (infusion / injection). If you were to be hospitalized for being malnourished, and if this were to happen, it is very treatable if identified quickly, so I wouldn't be too worried about it. Also, even though you've lost a lot of weight and have only been eating around 1,000 calories for the last month, that doesn't necessarily mean that you're malnourished to such a severe degree that you would experience refeeding syndrome upon increasing your caloric intake. This would depend on your weight, height, age, general health, etc.
I would highly recommend seeing both a physician and a psychiatrist for your condition ASAP! Eating disorders are nothing to play around with, and they are a very serious business. They can be life threatening and can cause a myriad of health problems in addition to refeeding syndrome. I wish you the best of luck in getting the treatment that you need.