Embarrassed - it usually has a relationship to being concerned about what other people think of you, also with concerns towards fear and a negative sense of oneself, depending on the situation. So for any type of fear the antidote is Compassion/Lovingkindness, the Unselfish Emotions. When we feel embarrassed we are usually elevating other people's opinions about us higher than our own opinion of what we think of ourselves.
One of the special mindfulness activities that helps for letting go of fears is to do a Compassion/Lovingkindness wish before we go into a room; then we already have developed an unselfish thought for others before we enter the room. So we are less likely to feel self-conscious, we are not so concerned about our image and projecting it; we are instead more concerned about feeling loving compassionate thoughts towards the people in the room. The meditation that I am going to be doing later this morning has to do with learning how to reflect on praise and blame in a wise way.
Looking at our intentions is very important in the process of letting go of our concerns about our actions. If our actions are skillful, if we have good intentions, then we are not so much concerned about what other people think of us. Also developing more confidence, reflecting on our good qualities, is very helpful for seeing both sides of ourselves; this is so that we don't always think of ourselves in a negative way. The forgiveness meditation that I did a couple of days ago is very helpful for looking at the past, at times when we were fearful and made mistakes. Fear is a deep human emotion, it's linked with the desire to be loved. So in order to lessen that tendency we have to learn how to love ourselves and have lovingkindness for others. Also having joy with ourselves and joy with others' good qualities.