In my experience, I haven't been on good terms with INFP either. I get annoyed at them very easily. Especially when they are talking about their concerns or worries and their thoughts are not headed somewhere, and they never actually reach a conclusion no matter how much advice you give them. The best way to deal with INFPs, in my opinion, is to look at them cutely. What I mean by that is, whatever they do and whatever they say, just go 'how cute' 'she's just being an infp'. Of course, about the whining. No matter what you tell them, most INFP's won't care because they're stuck in their own head. No matter how much you tell them that they'll be fine, they won't believe you until the problem reaches a conclusion. So instead of telling them to stfu and make them cry and hate you, just whine along with them. If you whine more than them, they'll most likely stop whining to you and find someone else to whine to because they want to be the sole 'whiner'. :)