single word for a person who makes things difficult

I am in search of word that exactly means 'a difficult person of my description'.

For example, I am on the look out for a heart specialist and ask my friend if he is familiar with any. However, he begins with the description of heart, its function, who can do without it, plausible threat from such doctors as are selective in their studies so as to skip 'heart' even and so on and so forth. I am lost in a maze, my head goes whirling and I fail to recollect what I was after.

Search among your acquaintances and you will find many similar examples. What I want is to give them an appropriate name–— preferably a single word.