Ok. You DEFINITELY need a lawyer. This is serious, especially if you're not a citizen. You can get a lawyer for free if you qualify for a public defender. Don't talk with anyone about this, especially police, without your lawyer present. A big part of a lawyer's job is answering questions like these. There is no way any of us on this site can give you adequate advice because we haven't seen police reports and don't know the complete picture. Don't try to do this on your own. Your freedom, your ability to be in the United States (and possibly your family's) is at stake. Get a lawyer to help you with this.
Again--contact your local bar association to inquire of low-cost assistance in the short term so that you have a better sense of what you are up against.