Self defense allows equal or similar force. If you used a razor he had to be using deadly force against you. If he was unarmed it will be tough to sell but not impossible. The witnesses will be important. Retain an experienced criminal defense attorney ASAP.
First, do not discuss this situation any further on the Internet as you have no expectation of privacy. As stated, you may have viable defenses. You need to hire an attorney as soon as possible.
Benjamin G. Kelsen IF YOU LIKE THIS ANSWER PLEASE INDICATE YOUR APPRECIATION BY SELECTING IT AS "BEST ANSWER." Law Offices of Benjamin G. Kelsen, Esq. LLC 179 Cedar Lane Teaneck, NJ 07666 Phone: 201-692-0073/ Fax: 201-692-0151 Web Site: www.kelsenlaw.com / Email: firstname.lastname@example.org NOT LEGAL ADVICE: The above information may contain an opinion which does not constitute legal advice. Unless a retainer agreement has been signed, we are not your legal representatives, and you should not rely on any opinions contained in this message.
Your use of the term "affirmative defense" is significant.
Let me start by saying you need a criminal defense attorney -- the charges against you are serious and could carry prison time. That said, an "affirmative defense," such a s self-defense, is one that when asserted, requires the prosecution to DISPROVE it beyond a reasonable doubt. In other words, they would have to prove this was not self-defense beyond a reasonable doubt.
Good luck to you.
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.