I think joining a support group would be a really good idea too. The group I have joined have been amazingly helpful and it's been great to meet people who I have so much in common with.
As for your parents, I can really empathise as mine thought that any kind of 'difference' or disability was shameful, so they just ignored my needs and problems and speaking to them about it was pretty much impossible.
There are 3 solutions I can think of:
1) Find a support group and tell them that you are going to go and, whether they like it or not, nature made you this way and you are entitled to seek support if that is what you need. (Also it shows your parents what a resourceful child they have!).
I do appreciate that this method may be a little too confrontational.
2) Find a group but don't tell your parents that it is an AS group. Say it's an art group, or that you are going there because you want to do voluntary work, or that it is a study group or something.
3) If it looks like the idea of a support group is really not feasable, I find that I get a lot out of websites like this (I can see you've made over 2000 posts, so I'm guessing you do too) so it may be that you have to rely on that as your main form of support - try to get as much support and communication that you want from fellow aspies online as you can without it causeing problems with your parents.
I'm sorry, I know that these aren't particularly great suggestions, and I'm sorry that your parents don't understand it as well as they could, but unfortunately this are the only possible solutions I can think of right now.
Well, good luck and I wish you well.