It is frustration, I guess. I go through it too, but have had to come to grips with my own loneliness and the fact that life has moved on without me. It is something to do with how we react to the natural progression of life when we do not live the cycle at the same rate as everyone else. It's something I have been thinking about for some time now. That life has certain times for certain things, and those who do not or cannot conform to the cycle are left behind as everyone else progresses at the normal rate.
To some extent, it can also be part of the burden of significantly higher intelligence than the rest of the world. A high level of intelligence makes you fundamentally different than the rest of humanity since your brain processes the world differently. The things most do on instinct , you will tend to question instead. Intelligence, therefore, allows you to break from the animalistic side of being human and focus more on the logical. Unfortunately, we live in a world of the instinctual rather than the logical. That puts you at odds with the majority of humanity and makes normal social functioning difficult. In order to function, you need to find other people who are intelligent as they are the best sounding board for you. I have often had this discussion with the other intellectual slackers I know. While I can't really converse well with the majority of those around me, I do have friends that I can converse with. I have 4-5 hour long conversations with them all the time. Our conversations have been about politics, religion, philosophy, etc. and not about things like sports or pop culture, unless it is to criticize them and those who are interested in them. The sad thing is that none of them has ever been a member of the opposite sex. Sadder still is that they have all been able to have relationships while I have not. Sorry if this does not help, but it is a reflection of some of what I have come to realize about this matter.
I will also say that you need to find something that fulfills you. If you don't, you will turn increasingly bitter and will become susceptible to drug and alcohol problems as a way of dealing with life. I have seen it happen to enough people to understand what happens to potential unrealized. I myself do not use drugs or drink, but have made a few mistakes along the way in my attempt to deal with life. For me, I usually write a lot in various blogs and on this forum as a way to deal with things. right now, for example, I am working on a philosophical conundrum dealing with the nature of man and what composes a person's personality. Where does it come from, and is it based purely on the biochemical or something more than that? What is free will, and can a person ever be said to have free will if biological factors control so much of a person's decisions and personality? etc.