Greetings,
The best advice I can give you is to contact your local prosecutor's office. Do it in writing. They will respond in writing. It will take awhile. However, when I want information pertaining to a legal issue that could result in my going to prison, I want a documentation trail. The police may give you an answer, but I can tell you from experince it may not be the correct answer. A defense attorney can give you an answer, and there is a very good possibility that it is the right answer, especially if you pay for it. However, it is going to be the prosecutor's office that will or will not refer charges on you, so their answer will be the correct answer.
In my locality I am not required to retreat in my home to prove intent of harm to a level of using lethal force. However, this does not hold true everywhere. Your prosecutor's office can give you the correct answer.