Your body is in starvation mode, you are burning WAY more calories than your body is taking in, as a result you body thinks that the food source as scarce and as a result holds on to everything it possible can. While it may sound counter intuitive eat more and you will probably start loosing weight again. When your body is functioning normally, i.e. not in starvation mode, woman burn 11 times their body weight in calories per day. 131 * 11 = 1441 and that is how many calories you burn at given no other activity, this is just a ball park and not an exact, and especially since your body is in starvation mode not accurate at all. But if your body was functionally on all cylinders you are burning an extra 1441 - 900 = 541 calories at rest, you also indicate your exercising a lot, not knowing how much that is, but just for having numbers to use lets say you burn and extra 300 calories while exercising each day, that means you are burning almost double what you are taking in, at 841 extra calories per day. A pound of body fat is 3500 calories which under normal conditions is a pound of fat every 4 days, or almost two pounds of body fat every week which is way to much and probably why you are in starvation mode. I would suggest probably upping your calories by 400-500 for the next week or two and see if your body starts burning fat again. Good Luck
You ve probably stopped losing because your body thinks you are starving it. 900 calories is too little, you should eat a minimum of 1000, prefurably no less than 1200 really. Try eating a little more and changing up your exercise routine, you could ve just hit an early slump.
Diets typically don t work (long term) because people reach their target weight, stop the diet, and return to their previous lifestyle; thus gaining the weight back and maybe more. To be honest, most of the diets out there use questionable methods and probably do your body more harm than good.There is no substitute for healthy eating and exercise. Losing weight and *maintaining it* requires persistence, dedication, and discipline. It truly is a lifestyle change. That s why most people choose diets; it s easier to get a quick fix rather than change their lifestyle.Perhaps you should checkout a dietitian and or a personal trainer.