As a parent, I'll say this: your parents WANT you to talk to them. Don't hold back out of fear of worrying them; it is their job to help you through these things, and they would much, much prefer that you share with them than that you don't. Parents can see when something is bothering their kids, so you can't keep them from putting you onto their plate of troubles; if you don't tell them what you are thinking, they'll be worrying about how to get you to open up, or assuming you have some other issue and trying to solve that, or ... Well, it comes down to this: it is much better for everyone to just put it on the table than to allow everyone to speculate, and speculate they will.
If it helps you organize your thoughts and helps you feel better to chat here first, great. Forums like this can help quite a lot. But I still hope you'll stop trying to protect your parents and will share your feelings with them.
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Mom to an amazing young adult AS son, plus an also amazing non-AS daughter. Most likely part of the "Broader Autism Phenotype" (some traits).