Can someone go with you to help you talk to the police? Even if your friend doesn't do any talking, it can help your confidence. I can have trouble understanding spoken words because of my sensory issues, and can have trouble talking if I am very upset. If you are a victim of a crime, or might soon be a victim, your local city or county might have a victim's rights advocate that could help guide you through the reporting process. If the police get hostile or don't want to talk to you, you might ask to speak to a detective or the police officers' supervisor (such as the duty sergeant, or precinct lieutenant or captain), especially if you feel like you are in danger. If you feel more comfortable speaking to a woman, ask for a female officer or detective. Explain that you are getting different messages from different people, and would like it explained to you.
If you are more comfortable communicating through writing, it might be good to write down what you want to say. Then you can either have them read it, or just use it as notes to help you talk. It might also be good for them to write down their instructions to you--it sounds like they are being very confusing.
If all this doesn't work and you think you are facing a serious issue that won't go away, there is also your local political representative who can look into your issue. That could be someone on the town council, county representative, or state senator (or MP, if you are British). I'd use politicians as a last resort though, as they can be pretty slow to react. Start at the most local level.
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Diagnosed Bipolar II in 2012, Autism spectrum disorder (moderate) & ADHD in 2015.