Rio, I think you're being too hard on yourself and rather negative. There is no one right personality profile for every job. Many jobs benefit from having a range of personality types. For example, you say you score as an introvert on this test and therefore you cannot work in teams as an engineer. A does not lead to B! You don't have to be an extrovert to work well in teams. Who told you that? I think you are placing too much stock in these tests. I am an introvert and have to work in teams all the time. Big deal. I am very effective at working in teams--my introversion does not hamper me. In fact, the structure of a team can be quite reassuring to an introvert. The expectations for interaction are clear. One type of person who does not work well in a team is the strong extrovert who always pushes his belief on others and can't see other points of view (the pushy, I-am-always-right extrovert who doesn't let other people talk--get these people off of my team!). My introversion would be more of a hindrance in a profession like salesperson, where I had to approach total strangers out of the blue and try to sell them something and risk frequent rejection. Just remember, you are young yet, and need time and practice to develop your skills. If working on a team doesn't feel completely comfortable right now, it can get better as you gain experience and success.

Rio, I actually think it is better if you don't take these tests, as it seems they are very discouraging to you. For your career, do what you love and it will most probably be a very good fit.