Because you got in one relationship, discussed possibly being poly then a week later (or few days) got a 2nd girlfriend.

Have you done any reading or research? Do you know how to be a good hinge? Have you shown your girlfriend research and articles that may help her.

You didn't let your original technically speaking Primary relationship build a solid foundation. You just jumped straight in.

Your friend will always be a trigger for her now.

She wasn't drugged, she willingly consumed drugs. And so did OPs boyfriend.

Sounds like he was very high and she was high and drunk.

It's not a clear cut situation because both were to intoxicated to consent. She claims rape, but so could he-as he was too inebriated to give consent also.

Plus she carried on having sex with him for another year, but says you're in the wrong because your now in a relationship with him.

I would block her and move on, sounds like she's trying to cause problems. Maybe her relationship broke down.