14 /12 /24

Hii, so erm. I have a friend who has uh BPD (Borderline Personality Disorder) and NPD (Narcissistic Personality Disorder) and like, I'm what he calls his 'FP' (favourite person, people with BPD usually have one) I know what an FP is, but like, during times when he like needs my help and shit I'm not sure on how to like support him?? I've tried to get advice from Google and stuff but idk I'm not really getting much. 

Is there like anyone with BPD or something that could like help me?? I want him to know I'm there for him but I have always sucked at comfort so like I genuinely have no idea what I'm doing. Anything is appreciated!! 

(this is so badly written ik I didn't know how to put it into words)