Ouch, Christian. You're embarrassing me. And all the INTJs in the world.
INTJs do not suffer from low self-esteem. It is impossible for an INTJ to suffer from low self-esteem. INTJs are the most self-confident and self-assured members of the human race.
In fact, we INTJs are often said to be arrogant, stand-offish and mercilessly blunt in our criticisms of others.
So what you are is lacking in social skills. Which is not an uncommon problem for INTJs. For INTJs do not have a natural understanding of social rituals. An INTJ boss, for example, does not know how to start a meeting with a few friendly words and a joke. He just jumps straight into the meeting agenda. An INTJ at a party does not shake hands and chitchat with people whom he knows he will never meet again. It would seem like a rather meaningless exercise to the INTJ. He'd rather just stand in a corner and admire the painting on the wall.
Fortunately for you, INTJs are phenomenal learners. INTJs can learn anything that they feel like learning. So if you feel like learning social skills, you will succeed in doing so.
To give you an example, in my younger days I was extremely introverted like you. I hardly ever said anything if I didn't have to. Speaking up in class was a huge effort, even when I knew the answers / topic very well.
Due to some random turn of events, however, during university I was once required to give a series of public speeches. To a large audience. No escape. Like a typical INTJ, I proceeded to buy two books on public speaking and then I practised relentlessly in front of a mirror.
I gave
brilliant public speeches. Each was better than the previous one. One thing led to another, and for years after that, people kept asking me to emcee their wedding dinners, their annual conferences, their company dinner & dance etc. I can do funny speeches. I can do serious speeches. I can do any kind of speech I feel like doing. I became a litigation lawyer for some years (I've quit now) and I daresay I spoke quite brilliantly in court too.
Now, you are an INTJ too. So you lack social skills. Nothing unusual for an INTJ. But being an INTJ, you also possess a tremendous ability to learn anything. You are already aware of this. For you wrote yourself:
im a programmer, i work much with computers, but im also a graphic designer, and an illustrator, im not focused in only the technical things, i try to learn many different subjects.
What you may not appreciate yet is that you are a very formidable learning machine. All INTJs are formidable learning machines. If you want to learn social skills, you can. It could be via a very "unnatural" method like borrowing a book about social skills, memorising seven key tips, and deliberately going to a party to practise those seven key tips, then going home to assess your performance. This kind of approach seems unnatural to other MBTI types, but it is very normal for INTJs to operate like this.
It's basically like how I learned public speaking.
So use your natural INTJ strength - the ability to learn anything - to overcome your natural INTJ weakness - your lack of social skills.
You are an INTJ! Like me, you are a very rare member of the human race, the rarest personality type of all! Be proud! Go do me proud!! INTJs rock!
And to all those who find me boastful, tooooo bad! I'm an INTJ. I'm made that way!