Friend wrongly accused of domestic assault

My friend (25 f) and her now ex boyfriend (32 m) got into an argument at her apartment. They both had been drinking (she had one shot and he had 3 handles of some sort of liquor) and things got out of hand. The only info I have to go off of is what my friend has told me, but she has no reason to lie to me. She said she heard him talking sh*t about her to another woman on the phone. When she confronted him about it, he completely flipped out and started gaslighting her. She was on the phone with another friend of hers while this was happening. He started screaming at her and getting in her face. She put her hands up to keep distance between them, and this prompted him to hit her in the chest. Soon after that, he walked outside and she locked the door. She then turned off all the lights and hid in her room. She said she heard him breaking glass bottles, trying to kick down her door, and trying to pick her lock. Her next door neighbor called the police (I later found out that the boyfriend had made good friends with the neighbor and had pitted her against my friend). When the cops show up, she hears them talked and laughing with the boyfriend. After they have talked to him, they enter her apartment and the first thing an officer says is “so what did you do to his face?”. The story this boyfriend told the police is that she is a crazy drunk and hit and slapped him in the face (he had cut and bruised his face while he was outside). They believed him, and arrested her. (Keep in mind that he is a felon and probably reeked of alcohol). She spent 12 hours in jail and he bailed her out. She was told that if she contacts him in any way, she will go right back to jail. He tried to wait for her when she got out, but was told to leave. He has since called her from at least 3 numbers, and showed up at her apartment. When she spoke with a judge to prepare for court, the judge said that it doesn’t matter that he tried to contact her, and that she could face up to 11 months in jail for this possible charge. Her next court date is Feb 2. I am so scared for my friend and want to help her but I don’t know if anything can be done. Does anyone have any advice? We are in Tennessee, and I don’t know what exactly our laws are on this because I’ve never dealt with something like this before.

Tl,dr: My friend was wrongly arrested for domestic violence (boyfriend was the violent one), does anyone have any advice on how to help her? In TN