Can anyone help me with my heartache? Im autistic...?

Give her some space for the time being, it'll do you both some good. After a few days to a week, send a message explaining to her that although you do have feelings for her, you value her friendship more and will do anything to keep that friendship thriving. Whether she wants to be with you or just be friends, you will still have that bond and you never know, maybe one day she'll return those feelings to you. Best of luck!