Cheer up friend !
I'm also suffering from such thing. The only difference is I'm a graduate.
I also had the same problem during my life as a student, which is full of unhappiness. During my primaries and secondaries, I didn't speak a single word- even when intimidated by teachers to speak. I was in complete isolation, without friends, being alone all the time. Fortunately, I managed to complete my studies as schools in my country (I'm from a South East Asian nation) normally do not call for much social activities.
My school life improved when I reached my 8th or 9th grade. Only then did I start to make a few friends. All in all, my school life was disappointing. Like you, I studied hard simply to divert my attention- and I'm a good student. I narrowly missed out to join the Medical School and I started my university life 3 years after my matriculation, during which time I stayed most of the time at home reading books, helping my family- that is, of course, to avoid more social contact. I read a lot of books on how to improve social skills, which I think was very helpful to me.
I was a completely different person/student at the university where I have so many friends but again let me emphasise that our education system rarely calls for much social activities. If a student can study hard he will pass the exam- no big researches involving social interaction.
I'm 26 now. I've been working for 2 years now but that is merely due to the good support I have from my family. If I need to find a job on my own, I will not get one.
The above-mentioned facts don't mean that I have recovered. No. Far from that. I'm worried, timid, afraid.....most of the time. Although, I smile most of the time in front of people, I may be in tears when alone simply do not know what to do. I may be talkative in front of some people who are close to me, even then I feel worried, shy, afraid... But with certain people(even those who are closely related to me) I become mute.
I think we (you and I) can overcome that. I'm not sure whether you're a male/ female, but being a grown-up male (ie at least what my age suggests), I can't go on like that. You also. You may sometimes wish that you're not born at all. But that wish can't be fullfilled. We might as well "fight" to live normally ! We have arms and legs as normal people, if they can do, why can't we?
I'm writing all this just to let you know that you're not alone. There is someone who is like you and ready to help you.
I'll try to make a list of things we should do to be a normal, dependable, socially capable person.
Hope to hear from you also. Until then, GOOD LUCK