ahh not gaining

ughh so i just went to the doctor's on wed. and they said i hadn't gained any weight! ive weighed 86lbs. for a few weeks now despite my efforts to gain (recovering from an ED). Right now im trying to work up to 1600 cals. and know ill need to get higher. but im suprised that my efforts to eat more (im probably at around 1200 now) havent helped me gain anything. My mom says i look like im losing weight wich frustrates me even more. is my metabolism just adapting to more food quickly? can anyone help? 

For most people, 1600 cals is the level they eat to lose weight.    So that's why you're not gaining.... you're still undereating.  You've probably boosted your metabolism a little with the extra food so you need to eat more to actually start gaining weight.  2500-3000 cals a day is recommended

Do try to plan your food day ahead of schedule.  Small meals and frequent sancks of high-energy, low-bulk foods are ideal.  Because then you'll get everything you need without feeling stuffed to the nines.  Ask mum to help you with it rather than trying to work it all out alone.   Oils, nuts, seeds, avocados, eggs, red meat, oily fish, full-fat dairy products.... work as many of those into the mix as possible.  Try not to fill up on too many low-calorie foods like vegetables and fruit. Obviously, keep active but try to avoid anything too energetic. Best of luck.