[Proud90sKid]

Hey, you seem to be having a cluster of issues. I think it honestly may be wise to listen to what your professionals have told you. I saw another post saying your parents allowed you to refuse intensive psychiatric help. Do they know about this issue? Because it is very serious. Eating disorders, particularly anorexia, are the absolute most deadly psychological condition you can have. Literally more dangerous than actively contemplating suicide. Your brain is made of fat. Lack of energy will harm it. Your brain is fully in the developmental years. When you don't eat, your brain atrophies instead of making new connections (same applies to adults too). This can have long term consequences, particularly at your age. This can slow or even reverse some cognitive development.
It is a much bigger deal than wanting to be skinny at 12. I am much older, but because of that I can say: there is nothing that could happen at age 12 that is remotely worth the consequences of this. My honest impression is that I think you need some sort of intervention to keep you from doing further damage to yourself at this age. You have an entire life ahead of you that functionally has not even started. Eating is a normal bodily function. Nothing to be ashamed about there. If you don't eat, that is much worse for you. Also, it is not even an ideal way to lose weight. You mess with your metabolism a lot by starving yourself. Your body tries to adapt by slowing your metabolic rate and cutting some corners by simply producing atrophy to the brain and other organs. Less brain matter, less caloric needs. Your brain is made of fat...in starvation, your body decides to use it as an energy source instead of developing it or allowing it to burn calories instead.

If you aren't eating, at least drink coconut water. It has very high levels of potassium, unlike other "electrolyte drinks" full of sodium. You need potassium to keep from going into a cardiac arrythmia. That is harm reduction, but won't stop the harm. It merely lowers the risk of one specific consequence. You need to be eating.

PE teacher doesn't seem to be taking it seriously enough. You aren't an adult who should be allowed to make life altering decisions, you are a child. Maybe they just don't know how unhealthy this actually is. Your parents should know about this.

Your hr teacher seems to know a lot more. Id listen to her. She isn't disappointed in you, just concerned.

I don't typically pay any attention to people's weight. If anything, being unhealthily skinny would make me pay more attention and not really in a glamorous way- I would just think about how sickly you look and would definitely be thinking about possible anorexia. Nobody is going to look at you and think you are just super fit and envy that. Anorexics look sick, like cancer patients, that's it.

It is scientifically proven that lower nutrition during developmental years hurts your adult cognitive and social functionality. It will actually start slowing you cognitively before adulthood and this can have social consequences as your friends continue to develop in a healthy fashion while you may be stunted. When I was 12, I sort of scoffed at the "brain isnt fully developed until adulthood thing", so I want you to imagine the equivalent for your age: imagine if you were cognitively stunted when younger and now you are entering your current age while mentally and socially behind your peers. That would be bad, right? You are still at risk of this if you stop your development by not eating.

Good luck. Id recommend dropping the goal of losing weight for now. You aren't going about it through healthy means and attempting that now risks being triggered to continue the relapse. It isn't defeat, but a refocus on healthy development. Recovery first, always. Your weight is not very important now. If anything, it is healthier to be a bit over than under at this age. Your brain needs nourishment now more than it does in any future time of your life. Overweight or obese is a very small problem compared to a starvation disorder. Id even go so far as to say you should stop getting on the scale at all. All that will do is trigger unhealthy thoughts.

Weight loss can be addressed later. There is a famous former Sumo wrestler who was highly competitive(and VERY heavy) that has now dropped himself to a good weight using healthy means after retiring from the sport.