A relationship, in the simplest sense, refers to some kind of interaction between two people. For this to be effective the needs of both people must be satisfied. For example, I want to buy and you want to sell, I don't want to appear friendless and alone at the party and neither do you. These interpersonal interactions can be quite simple or really quite complex. Moreover, they can last a few seconds or a lifetime.
Fear in relationships takes two forms. The first relates to the fear of being unable to control the impression we make. The second is the feeling of fear that we can't identify where it comes from or even why. We tend to refer to the first kind of fear as nervousness and the second as anxiety. Either way, they can seriously hamper the effective trade-off, the give-and-take, necessary for communication.
Unpick a conversation and it's possible to see certain patterns emerging. If I pass you a complement you show some pleasure, if I ask you a question you offer an answer. These patterns of activity are embedded from a very early age and we find ourselves almost compelled to use them. This knowledge is understood by sales people who, completely unannounced, telephone or arrive on your doorstep and ask ‘how are you?' It's a completely bizarre situation having a total stranger ask such a question, but such is our social conditioning we probably find ourselves answering. A social transaction has then taken place where we're hooked in by politeness or the wish not to offend. Once we get wise to such a ploy things can quickly change. It becomes far easier simply to hang up the phone or say ‘no thank you' and shut the door. Why? Because this particular form of interaction is weighted almost entirely for the benefit of them and not us.
Back to our conversation. A successful interaction is likely to be one where both people's needs have been met in some fashion. But, if one or both people are feeling anxious the outcome may be very different. Anxiety has a way of inhibiting both comments and gestures because the anxious person is much more driven to lessen their anxiety. This isn't what a conversation is about and so a common outcome of imbalance is often irritation or frustration, which leads to embarrassment and further anxiety.
What's needed in such situations is more rather than less practice. Anxious people often have a self-damaging form of inner talk that tells them they aren't competent enough or clever enough to maintain the conversation. They probably think the other person will think they are saying stupid or irrelevant things or may even be offended by their views. In fact the other person is probably extremely keen for you to interact with them because they need positive strokes too. Break into the anxiety cycle by concentrating on behaving more confidently and trying to physically relax rather than telling yourself off or trying to think your way out of anxiety.