The DA has charging immunity which means you can't force to prosecute a case he doesn't wish to prosecute. In any event it is now too late as you have missed the many filing deadlines that apply in suits against government entities.
You cannot sue prosecutors under the sort of circumstances you have outlined.
In no way am I offering you legal advice, and in no way has my comment created an attorney-client relationship. You are not to rely upon my note above in any way, but insted need to sit down with counsel and share all relevant facts before receiving fully-informed legal advice. If you want to be completely sure of your rights, you must sit down with an experienced criminal defense attorney to be fully aware of your rights.