Stay away from her. Completely. Forever. She won't be able to put you in this position again if there's no question that you weren't anywhere near her. As to the current case, speak to an attorney.
If there are no witnesses and you made no incriminating statements than it is her word against yours. You said that you completed classes before so I am assuming that you were previously convicted. This makes it more likely the DA will want to prosecute. Anyone can apply for arestraining order. You probably have an EPO emergency protective order against you at this time if the victim requested one. The court at your court date will likely impose a CPO criminal protective order since the EPO expires after 5 days. Definitely consult with a local attorney and good luck! The consultation is normally free and you can find an excellent attorney through this site.
Normally, prior conduct doesn't factor in and isn't admissible, but in domestic violence cases, Evidence Code 1109 may allow the prosecution to introduce your prior situation in the case against you. Given that you have a prior conviction for DV, they will probably be much more likely to file the new case against you, even if it is "he said, she said".
If you don't care about being with her and plan to stay away, then the restraining order won't be an issue. However, it gives her power over you. One phone call alleging you violated the terms will land you back in jail and with new charges. You don't need that.
I'd strongly suggest you consult with a good, local criminal defense attorney to discuss your situation in much greater detail. In the mean time, please do NOT have any contact with her - you'll only regret it.
The above answer is for general information only and is based on the information you posted. Every case is fact dependent, so to get a thorough analysis of your situation, you will need to consult face to face with an attorney licensed to practice in the jurisdiction where the incident took place. Do not conclusively rely on any information posted online when deciding what to do about your case.