I'm sorry about your mum. How about your siblings? Can they be with her? Surgery isn't something she should undergo without a close relative by her side. Nonetheless, I pray all goes well with your family.

As for the narcissist, if you are very sure, your friend is all you have mentioned, dine with him with a long spoon. I just don't have faith a narcissist won't emotionally traumatize you before they break ties. From my experience, I don't regard them as friends one bit.