Anorexia Recovery & Treatment

I just started a partial hospitalization program to recover from anorexia and i really need to gain some weight. (I am 17, 5′4 and 80lbs, but i have never weighed past 87lbs in my life- i guess i just grew and never gained weight). Anyways, i’m not sure how much weight i will have to gain before i get out of this program and can go back to school, but im thinking maybe like 15-20. My fears are, the other girls who are further along in the program have to eat soooo much food. The dietician said it’s because that once your metabolism gets going again, it goes into overdrive. So im concerned about having to eat that much just because i dont think my stomach can handle it. I am on a lower calorie plan to start, but even now, my stomach hurts and i get really bad gas after i eat my meals there. Will this improve? Also, if i gained the weight, will it be evenly distributed? Will my breasts still grow? I also hope to do a little strength training once i get out of the program, but for now im not supposed to be exercising. Is this ok too?
Sorry for all the quesitons. Thanks for your time

my parents still dont know.
i developed bulimia nervosa six months ago. i was bulimic for about 4 and a half months, no recovery, no telling parents, just stopped on my own.
i constantly am starting to think about my weight, im making meal plans thinspiration. i didnt eat at all one day and then i had 180 calories in 2 days.
my calorie goal tomorrow is 520.
i purged today and yesterday.
i excersise everyday, i want to starve myself and im terrified of gaining weight. but deep down, i feel like i want attention of some kind.

When i entered recovery for anorexia 4 weeks ago i was 5′8 118 pounds and they put me on meal plan c (2000 calories) because i needed to gain weight and because i was exercising alot. A day after being told i needed to follow that meal plan, i was told by my doctor that i could only go for walks because my heart rate was 41. now, 4 weeks later, i am at 122 lbs and they just changed my meal plan to meal plan b (maintain weight) because i still cannot exercise; not because of my heart, but because i was over exercising last week when i was told by my doctor it was not safe to exercise. My question is, now that i am on meal plan b (1800 calories) and not exercising wont i gain weight? why would they put me on a meal plan to maintain weight if i am going to gain weight from it?

ive been in anorexia recovery for a little over a month
the first program i started with they had me count my calories i had to have 1500 a day
then i came to california and joined a diffrent program
we are not allowed to count calories
we have meal plans which are called exchanges
we have to have a ceratin amount of starch(6) protien/meats(3) fats(3) fruit/veg(5) snacks(2)
but i still count calories
i really cant stop
im too afraid to tell my nutritionists and therapists at therapy groups and stuff
im scared
i dont know what to do
should i just tell them?
its not like they can do anything right?
please any advice is greatly appreciated

I re-started my recovery yesterday, narrowly avoiding a re-admittance, however i am still on admittance list if i slip up because they said this is my last chance. My BMI is 15, at aged 16. I am going straight back onto a full meal plan. This may seem extreme and sudden, but i actually think its best for me. The only problem is i am gettin a lot of trapped wind and sever stomach ache. I get dull aches as well as a stabbing pain. What can i do to relieve it?
Ive also noticed a sudden increase in bowel movements, including diarohhea.