I have a very similar experience. I was admitted to a hospital and my ex admitted himself to find me there. I got transferred to other hospitals where he would find the number and call repeatedly saying he was different family members. He now tells everyone (unfortunately I know people who he still knows) that I'm his psychotic ex wife. I was 16 and he was 20 so there was obviously no way we could have been married. Some of his last words to me where that I "put his heart through a blender and pressed frappe" (through all he put me through I can now just laugh at that sentence). He continued stalking me until I moved, and tried to find me at random places. He got with one of my best friends (who was a floor away when he tried to kill me and heard everything), and she got away from him eventually. I tried to explain how he was to her (even though she had a pretty good example already), but he was charming, and a convincing liar. Unfortunately, you can only do so much for those kinds of situations. I hope you feel no guilt. Reaching out to her was the most you could do, and keeping yourself safe at this point is a priority. I hope you have found peace!