A relationship requires both parties' desire and commitment. It will never work if only one of you wants it to. If she has said she doesn't want to get back together then sadly you might need to accept this and find someone else. From my knowledge of people with ASD (I've been with someone for two years who has it) they don't always value or retain emotional connections like NT people. Sad to say it, but she said no to trying again and for her there might be no grief or regret for the end of the relationship.