I think yours is an identity crisis more than anything. Have you ever wondered by whose standards are you measuring your "inferior" self against? And on what basis do you conclude such yardsticks to be the appropriate benchmarks to be measured against? Look, if you were talking in pure academic terms, I suppose I could still understand if you failed to measure up in terms of your grades(at least, there's something tangible even though it might not be a comprehensive and accurate reflection of one's ability), but how you could find an 'acceptable standard' to measure your personality and character is just beyond me. Taking your last point about emotional detachment as an example, it's pretty obvious there isn't a particular type of person who would fit into all sorts of social setting - case in point : oftentimes, a talkative person is unlikely to get on with a quiet one without the pair ever regretting not getting to know the other party(quite simply, the quiet one will probably view the loquacious chap as being too noisy for his liking and likewise, the talkative chap viewing the quiet bloke as too reserved for him). Hence, is there even a realistic chance of having a 'perfect' conversationalist who could appeal to both the quiet and the talkative chap? You just can't ever please everyone in life, can you?

First and foremost, I think you need to resolve that ambivalent dilemma more than anything - what is it you really want and what are the things which constitute being acceptable?
Personally, I don't see how this "IÂ’m likeable enough for most friends to behave cordially towards me, but not enough for them to include me in their social life" syndrome should ever affect anyone. The reason being human relations and chemistry between people work in such subtle ways I don't believe going out of your way to fit into the culture of others is ever a solution to your problem, even if it's fuelled by a deep sense of insecurity. I mean if you had some common interests with those whose social circles you're trying to be a part of, I can't see why they wouldn't want you in them. That said, if you're not a part of their social circles simply because you do not share their culture(which is most probably the case anyway), then I don't see why you should feel desperate(and dejected when you don't succeed) to be a part of the group either. In truth, you're probably better off not being a part of someone's life with which you cannot really identify with and feel miserable being anything but yourself just to accomodate him/her.
Don't read me the wrong way though because I'm not trying to encourage you to be anti-social by any stretch of the imagination, but I think it is imperative you understand(and this isn't rocket science

) that it is not likely you'll find an intellectual in the company of street thugs; a teetotaller in the company of alcoholics; or an atheist in the company of preists. In essence, do mingle with people if company is what you seek - however, do not feel compelled(and deem yourself a failure in the process) to fit in with a particular group if there is simply no chemistry between you and those whose lives you wish to be a part of. I'm sure there're enough people out there for you to find those who share your interests, passion and values.
I suppose if you could resolve the ambivalence in you, points 2 and 3(ie.relationship and emotional detachment) will pretty much take care of themselves. When that happens, I don't see how you could be that bothered by your physique anyway given you'd probably feel more confident and less inferior.

As Bill Clinton famously remarked, "Life is shaped by the opportunities you turn down as well as by those you seize."
