Look for areas of communication breakdown in your life. You could write entire books on the subject. In fact many people have, and it wouldn't hurt to visit your local library to check out a few, but basically, the social part of our nature is a muscle. Like any muscle, it has to be worked. Force yourself into social situations.
Shyness is easy to diagnose.
Other areas of communication breakdown can be far more subtle, and require us to honestly look at areas of our personalities it might be easier to blame on others. Don't blame insensitive managers. Look instead to yourself. Understanding the signals other people send is at least half of good communication. You have to repeat yourself three times and draw them a picture, nothing seems to help.