The victim won't show so why should I worry?
This may or may not be true. But it may or may not matter. Unless you know for sure that the city or state (whichever entity is prosecuting you) cannot proceed without a victim, then there is a chance the prosecutor can proceed. And many times, it can. With 911 calls, photos, excited utterance exceptions to the hearsay laws, the state may be able to proceed to trial. And if you don't have an attorney helping you, you might be in significant trouble when it comes time for trial.
I'll just tell the judge what happened and everything will be alright.
There are two problems with this. First, you should almost never take your case before a judge when you can take it before a jury. There are some exceptions to this, but most of them are relevant only to graphic rape or sex abuse cases. I have handled thousands of domestic violence cases. I cannot think of a single one where the defendant was better off before a judge rather than a jury. Second, your ability to "tell the court" your story is governed by the rules of evidence. Unless you follow the rules, your evidence doesn't go before the judge or the jury.
I have a legal defense to my actions so I don't need to worry.
It may be that you have a legal defense. But you may not. Legal defenses are things that you need to plead before the court and sometimes, for some defenses, the burden is on your to show that they exist. If you can't do that, no defense gets presented before the jury.
The judge or the jury would never let me be convicted.
The judge is not going to help you. If you have a valid legal defense and you can't present it to the jury, that's to bad for you. The judge won't protect your rights unless the prosecutor crosses so far beyond the bounds that you are toast anyway. And the jury, many juries I worked with as a prosecutor against a pro se defendant ended up hating the defendant. Most felt sorry for him too, right after they convicted him.
Get an attorney
An attorney will help you with your case, work with you on your defenses, be able to make your evidence effective in front of the jury and keep you protected from the prosecutor. Get an experienced Domestic Violence attorney and protect your rights and your freedom.