mibjkk, good for you for breaking down your specific problems with socializing. I had these problems for a long time, but I was way older than 20 before I recognized that it was indeed a problem on my part, and not everyone else's.
When I do talk enough, I fall into a few pits. I either: a) Talk primarily about myself. b) Offer unsolicited advice and sweeping generalizations about other people's situations. or c) bring up boring topics like the weather
The best thing I ever learned about socializing is to shift the conversation to the other person, and the things they value. People love to talk about themselves and the things they're interested in. If you make an honest effort to understand what is important to them, they will love you for it, and will be very receptive to anything you have to say.
In a working situation, such as with your boss, see if you can find out what's on their mind. What issue are they concerned about at the moment, and what can you offer in terms of understanding and appreciating that concern.
In other words, forget yourself. Engage with what is important in that other person's world, and you won't believe the response you get. Forget trying to manipulate the impression you make on them. Just offer your understanding, as a gift, and you'll make the best of all impressions.
By doing this you will be accomplishing all the things you wanted to do, without being self serving. You will be conveying your value to others, you'll keep them interested (because they get to talk about what they want to talk about), and you'll be creating a positive emotion in them because it is so gratifying to be with an understanding person.
I talk about ways to do this in another article called
The Secret to Connecting With People.
Thanks for linking my article, recordrustle. As I say in the article, I used to be quite shy and now that's changed fairly quickly.