How to overcome embarrassment about speaking English.
1. Identify specifically what you are embarrassed about. (your pronunciation, lack of self-confidence, fear of being thought of as stupid, etc.)
2. Address the specific problem. (Improve your pronunication by reading out loud, listening to video and audio files and saying what you hear out loud; search for resources to improve your self-confidence; ask yourself what is the worst thing that could happen if people thought you were stupid, incompetent, etc. Does their opinion matter?)
3. Find a language partner or teacher that you trust to build your confidence, someone with whom you can feel comfortable making mistakes without worrying about criticism.
4. Practice, practice, practice.