As I understand your post, no charges to your knowledge have been filed yet. Accordingly I don't think you need to retain an attorney at this point, but I strongly recommend that you at least talk to one of more qualified criminal defense attorneys in your area. Most here offer free, if limited, consultations. Take advantage of that to talk privately with one or more of them to get an understanding of the options likely open to you in the event charges are filed. Because you believe you were in the wrong does not in any way lead to the conclusion that you don't need legal representation. There are likely going to be multiple options open to you in the event this thing moves forward. You want to have the most favorable outcome possible because longterm negative consequences to your future may flow from this depending upon how it its handled. Rolling over an allowing the system to do whatever they choose with you is a really bad play. Good luck.
First, do not post another word about this on a non-confidential message board. Second, if you get charged, you need a criminal defense attorney. Third, none of us can predict whether a warrant would be isssued for your arrest should charges be coming.
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.
Most definitely you will need a lawyer if you are charged. Assault is a first degree misdemeanor punishable by up to 180 days in jail and/or $1000.00 fine. It is an offense of violence that will impact your life. Hire a lawyer.
You can be charged with a criminal offense from this incident even though the police did not come out and arrest you that night. The police may likely contact you to "investigate" the Complaint. You do not, and should not, answer any of their questions. You may politely "decline" to talk to them and walk away. If they insist, tell them you want to talk to a lawyer before answering any questions. If you voluntarily talk to the police about the incident, understand that they are only trying to obtain evidence to prove you committed the alleged criminal offense. Cooperating with them doesn't get you out of trouble for it, no matter what they say. Police officers are allowed to lie to you: that is called "investigation." They are not interested in "helping you out of the situation." They do not care what happens to you. Their job is to "investigate" and "obtain evidence" of a crime. If you talk to them and admit anything, you are simply giving them the "evidence' they need to prosecute you for the offense. Keep you mouth shut. Demand to talk to a lawyer. Say nothing. If they are going to arrest you, let them do it and go hire a lawyer to help you. Do not look to hire a lawyer after giving them all they need to arrest and convict you of the offense.