You need to seek professional legal advice... If you haven't been given a solicitor, then you need to find one. If you have, you need to be insistent on them giving you enough time to explain what happend fully.
Your explanation of what happened above seems confused and a little incoherant. Thats going to make it difficult for your solicitor to understand the situation fully, and for them to help you. Not to mention making things more difficul if it goes to trial.
You need to give your solicitor a clear, easily followable account of what happened, and also a similarly clear account of what you told the police: - spelling out the differences so they really notice them.
Before it does go much further, you'll be given a big bundle of documents detailing the evidence against you. At a minimum I'd expect this to have a statement from the prostitute, (and will likely have statements from the police officers involved, and any other witnesses) that will tell you exactly what she says happened. Read this *very* carefully, along with everything else your given. Get your solicitor to help you understand anything in there that you dont.