I honestly doubt you, so much.
If, as you state, you are 15, your legal guardian would know about your illness (if you were in care, your social worker or care provider would probably know too), because until you are no longer a minor (18 in most US states, 16 in UK and several other EU countries), it's your parents or legal guardian who decides your medical treatment (unless you have medical emancipation).
If you are 15, as you say you are, where are you "staying on your own"? If you were living alone, I'm fairly sure that social services would have been involved by now? Maybe even the police (if you'd been reported missing by someone).
I'm also fairly sure you can not receive treatment as a minor unless your parents/legal guardian agree to it (I couldn't see a psychologist a few years ago unless my mum gave permission - I was 14).
Your story is highly illogical in many parts. Surely you are old enough, at 15, to know that your legal guardian gets to make your medical decisions until you are 16. You are also old enough to know that if you are "staying on your own" you really shouldn't be. I mean...where are you "staying on your own"? If you mean you're staying in your bedroom, I apologise.
But your story has great big holes in it.