Hi there, I think I have missed the main flood of replies on this post. I have to say, reading your post took me on a horrible flashback to my year 10. I lost a lot of weight within a year: looking back on it I can only really put it down to the stresses in my house at the time (2 parents that argued constantly and a family member with at-the-time undiagnosed Bipolar disorder having psychotic episodes) reducing my appetite. I went to Dr with my mum, to reassure her and instead they referred me to CAHMS, (a 1 hr bus journey either way, only on school days). That trip ruined my life. I didn't have any of the typical associated MH signs of anorexia other than a low weight. However, no matter how I felt, I was still a low weight for my height at the time and was trying to improve it . No one tells you how hard it is to gain weight when you are trying to (and believe me I am no sporty in the slightest). I was 49kg at that point but that was pretty low as I was 5ft 8 or 9 at the time I think.
I really didn't want to go cos I felt I could help build my diet up monitored with normal nurse clinics. I was also terrified of falling behind on my GCSES like you. I knew for the career I want to go into, the unis need top grades and I didn't want to have a 'black mark' of a mental health label on my application forms (just to reassure you, this has not been the case at all and it did not adversely affect my application). However, I was blackmailed into going, told that they would bring social services in to investigate my family and might also be put under section (was actually a long way from this point at the time, from what I now know). Things deteriorated and by the time of my cahms assessment, I was told I wan under no circumstances allowed to attend school. Being the sad human I am, school was my life. I loved to learn, didn't really like to do what other girls did at weekends and used the breaks to stay in touch with my busy friends. Taking that away, I still adamantly believe, was the most significant factor contributing to my hospitalisation.
I lost any motivation, had no other activities to do and school stopped sending me work to do so I constantly fretted about my exams and pulled all-nighters (also low weight is not great for sleep etc) printing any kind of revision from the internet to do. Weekly treks across to the CAHMS were a drag. I hated the staff because all they saw was someone they labelled with an ED in denial (they probably see so many people with that scenario before) and they had no respect for my opinions at all. I did not improve. I was so stressed, got worse and was hospitalised in the end. I was inpatient for 7 months, discharged on my 16th birthday and have felt constantly watched ever since, especially while I was at 6th form. I also missed out on so much banter and was basically a social pariah when I came back. I missed the end of year 10 and the first half of year 11 and my head of year tried to make me quit my twilight latin class. However, I ended up with 11 grade 9s an A* and and A^ (was the 1st year of all subjects being 1-9) so I totally did not fail. Now I am at uni but having that hospitalisation on my record made applying really stressful as I didn't know if they'd want someone who was ever that bad in the profession (I know they can't discriminate but still)
Missing a day every week to trek over to CAHMS now is SOOO annoying I know but it is better than refusing to go, dragging other authorities in to look at your case and then ending up in an inpatient somewhere, missing months on end. Trust me, you will catch up. Don't waste energy worrying about grades now: focus on regaining weight and then you can knuckle down on revision.
In my experience, they will NOT let you argue with them as in their psychologist heads, that would be allowing the ED to 'negotiate'. Sorry to be frank, but whist you are under their care, they will listen to your rants with a sympathetic nod and then blatantly disregard your opinion because they wouldn't want to be held accountable if your weight slipped, you had a heart attack or similar and you died.They probably won't discharge you until you are properly stable either. I had to attend CAHMS again after my inpatient treatment (was mortifying!) and could not WAIT to leave the tacky quotes on the walls, the musty smell and the two-faced clinicians behind. We kept having to cancel appointments as we couldn't travel over there and in the end, we just stopped arranging them because they became too infrequent and we both hated eachother. Officially, I don't have a discharge letter cos they were so reluctant to let me go. The only reason I got out of impatient was because I realised that they were never going to accept anything from my point of view and were always going to interpret what I said in the context of an ED (thus putting words into my mouth).
My advice: Play the game. Gain the weight and more. Eat lots of nuts and nourishing foods (also a great excuse to eat peanut butter- YUM!). Splash a bit of cash in starbucks and on any foods you enjoy. Show them you don't have a problem. The faster you show you are complying (even if you don't agree with what they are saying in the first place), the faster you can stop going to CAHMS, and they can see others who might actually need mental support. And don't stress too much about grades- you sound like you are motivated so just do all you can to catch up.
Please don't let yourself get sucked into the same situation as me and just do what they tell you. Your future self will thank you for it.