S., either ignore it all, or move out. There's no in between here. Your MIL and FIL are too old to appreciate all this. They have been there, done that. They need some peace. All this is getting on their nerves. If your MIL wrote in on here, can you imagine what her rant would be? I'm sure they didn't count on having to share their home with their adult children and a grandchild. They DON'T understand autism. They may never understand it.
That being said, you probably didn't count on living with inlaws for years on end when you fell in love with your boyfriend. You sure as heck didn't count on having an autistic child. It's done now, and what you need to do is work the finances out so that you can go get your own place and get support services for your daughter. Putting some space between you and the inlaws would help tremendously.
Ignore anything from your MIL regarding what your husband does for the baby. Ignore her telling you not to take breaks. YOU tell your husband that you are going to see your friend. If he lets the child sleep rather than take care of her, make HIM stay up with her all night long. Make your husband responsible for his child, and don't listen to a thing she says to you about it.
Until you can stop fighting in your mind about defending yourself and being angry at this circumstance you have put yourself into, you will never be happy. Either get past it, or move somewhere else.
Good luck,
Dawn