I was about to offer advice but then noticed the post is over 100 days old so I guess...what happened?
I have had 1 very close infp friend on and off for a total of 7 years. When we were good we were good but when we bad it seemed like she was fire and I was gasoline. No matter how hard I tried to help or reach out to her it became worse.
Im not a d&d player so some of what you said was lost on me but I understand why she was upset by what you said. Infps (from what I've read and seen) have very deep passionate emotions. If you hit on a nerve they strike back hard. I've always liked infps and want to get a long with them but it never seems to work so I don't know if I can offer advice or if you even need it at this point
Idk