I feel for you, Gamma V, because in fact, my husband is like your parents. Even though I am an adult, the amount of rows I have had in order to take care of MY body.
What I have to resort to is cunning, sadly. So, I have given the impression of taking something, when, in fact I have not and this happened with medicine for overactive thyroid. I did not want to take the medicine but my husband said that if I did not, he would not even entertain the thought of taking me to a homopathic dr; close to where we live. In that situation, I was not cunning. I did take the medicine and infact, it worked. Within a DAY of taking it, I found I was a lot less weak. I went to each appointment diligently, but my thyroid then went UNDER active and the worst part was this was NORMAL; so they were playing with me, basically and I got fed up of it, so I decided that I would stop taking the medicine and any sign of that weakness returning, I would take it and it has not returned. I had to explain to the dr, but happily, I had worked out that she would ask and so, had formulated my answer and she accepted it. My husband was vastly surprised when I "confessed" that I had not taken the thyroid medicine for months.
Now, I was on prozac for 16 year's and my dose was constantly being elevated. I suffered terrible depression and migrains that reduced me to bed for 2 days and severe vomiting. I gained a lot of weight, because of that and hormonal tablets. My dr NOT ONCE talked to me about it ie change to something else etc. I had a feeling something was not right and so, had tried to stop a few times, but the horrible whirling in my head, coupled with the sensation that my eyes kept freezing into place, panicked me, and, so, I started up again.
Not sure what it was that caused me to take the brave step of cold turkey, but I did and I suffered a month from up to 5 panic attacks a day and my goodness me, the whirling sensation was frightening. However, my husband took the information away from me, in case I would over read and each "symptom" that came along, he would confirm it was the withdrawl effects.
A month later: absolute calm and the depression lifted and the headaches disappeared. I lost a bit of weight and not as tired as I had been and that told me, that it was the prozac.
There are two types of depression. Clinical and social. I had social and still have social, but rather call it meloncholy, because it is NOTHING to what it used to be.
Getting that explaination out of the way. I know this is not going to be seen as good advice, because it means going against your parents, but sadly, sometimes one has to and so, I would PRETEND you are taking the medicine. I know this is hard for an aspie, but desparation can make us rise above a situation.
If your parents do not demand to see you take your medicine, you have a better chance at "keeping up appearances".