Hi Sheba,
It's good to hear from you again! I'm sorry that you're having difficulties getting your parents to understand you. You are correct in that you must make your own decisions.
Your parents have difficulties understanding you partly because they don't want to and partly because they are afraid for you.
They've made decisions for you while you were growing up and feel they can continue, that's the not wanting to understand. The afraid part comes in because they don't have any way to make sure you succeed if you go your own way.
They have yet to understand that you are entitled to independence from them. They can't understand why you wouldn't want their help. It is difficult for alot of parents. It's difficult for me. I tried to get my daughters to "see things my way" and put myself through alot of anguish because of my fear of "what would happen" to them. It wasn't until I realized that I had no control over this and they could make their own decisions, my parenting days were finished. The issues I have with my younger daughter stem from moral and ethical issues, I do not support what is against what I believe. As far as how she wants to live her life, I have dropped the apron strings, for better or worse.
You said that your parents have alluded to health issues you are causing - true? This is a form of manipulation whether they are aware of it or not, and regardless of whether they are are having issues or not. My reaction to my daughter's rebellion caused me health issues and their reaction to your independence is causing them health issues. Your independence isn't causing the health issues, you can't carry blame for having a difference of opinion. Your parents are being unfair when they say you are causing their health issues because they are saying that you can hurt them by having a difference of opinion than they do. If you are respectful in asserting your independence and your decisions are not meant to hurt your parents you have done all you can. You aren't responsible for the fact that they are unable to accept what you are telling them.
I hope this issue gets better for you Sheba. It's a difficult one and the struggles are very real, but they will pass. Hang in there!