I am sorry your son is so sick. I know that you feel judged by this thread and it sounds like you were judged by your community, but I just want to say that I find your situation unique and different then what I would consider as a helicopter parent.
In no way would I consider what you have to go through or had to go through to advocate for your son as being a helicopter parent.
An example of a helicopter parent would be: A parent who has to have influence or hand pick a child's teacher every year. Who has to intervene, constantly, in situations that the child could probably handle on their own. For example: Child says: Susie hurt my feelings at lunch today. A non helicopter parent might discuss what happened between the children and give the child suggestions on how to effectively communicate her thoughts and feelings to Susie without ever actually getting involved. A helicopter parent might call the teacher and reprimand them for allowing it to happen, call Susie's parents and try to manipulate the situation to their own child's favor, basically try to mold and shape the environment to their child rather then teach the child how to adapt to the environment.
That is just one example, there are many more. I am sure you have had to encounter these type of parents before.
As far as your situation goes, nobody knows a child better then the child's own parent(s). If you know something is wrong, you don't have to defend yourself or prove yourself to anyone. All you have to do is keep your child safe.
I am glad you listened to your motherly intuition, which IMHO, is worth it's weight in gold.
