You are not inappropriately selfish at all. You are taking good care of yourself.

I hope you do stay at a hotel and not at her place.

With my sister I had to point her in the direction of professional help - social services, therapy, etc. I'd remind myself that getting re-traumatized while trying to support my sister wouldn't help anyone, that there is plenty of help available, and that I'm not a therapist. Even if I was, I wouldn't be seeing my sister in therapy!

I figure that especially the more dangerous a potential situation is, the more that professional help needs to be called in.