Damn RK this looks like a shitty situation.
Does it looks like she'll press charge? Consider recording your conversation with her, get her to say it was consensual.
Try to get what's app logs of you two taking. Try to get logs of you two agreeing to see each other after the "rape". Try to get her to write that it was all consensual.
Especially don't panic. Stay calm and focus on getting her destroying her chances to make anyone believe you raped her.
Don't get violent, don't yell. If you must threaten do it calmly, so no one could day something like "I heard him yelling at her, maybe he even hit her" or something.