You are 18 and therefore an adult now (although you may not feel any different than you did when you were 17). Basically, one of the beautiful things about being a grownup is that you don't have to run everything by your parents any more, even if you still live with them.
Still be respectful, and certainly tell them if you'll be out, if you'll be late, etc. as that's common courtesy so they won't worry. Always take your phone and answer if they call. If you say you'll be home at 11 or 1 or whatever, make sure you are, or at least you call and tell them you'll be late.
At some point, despite your issues, your parents will still need to start letting you make your own decisions, and that includes who you are friends with and what you do together. If you aren't in any physical danger and if Laury or anyone else has been good to you, then their objections are really without foundation.
Whether they want to admit this or not, they will not be around forever to save you from yourself. Even if you will live in a group home situation for your entire life, you will still have plenty of time where you are the one who has to make the choices and live with the consequences.
Being an adult also means you have to deal with disappointments and failures, and it's better to deal with those when you are young and it's often on a smaller scale, rather than when you're older and it can be devastating. Yes, people need practice failing and picking themselves up, dusting themselves off, and getting right back into things.
Another thing is that you could be in some ways misinterpreting their intentions and/or their words. From your posts here, you seem to be shy and unassertive to a fault. I know it can be a hard thing to do, but the truth is, you will need to become more active in your own life in order to get what you want and need. And maybe what you see as them 'hating' your friends, they may see as an effort to get you to start sticking up for yourself and not letting people dictate your life to you.
Your life (as would anyone else's, autism or no) will be a helluva lot better if you take charge of some aspects of it, and don't just let yourself be buffeted by every breeze and current out there.
There is nothing selfish or bad about standing up for what you need, think, and believe.