How can I express what I feel without getting boring?

Communicating. I suggest you find an appropriate person to express your feelings to who can be sympathetic to your situation. Remember, men are not trained to listen to people's problems with understanding. They want to "fix" things. And if people hear your problems too much, they may become disinterested. It is not helpful just to ventilate if you have no plan for repair. Professional counselors can help.
Listen to others. In addition to expressing your thoughts and feelings with your friends, you should practice listening to them and drawing them out about themselves. When people talk about themselves they rarely find the listener boring.
Expression. I can't imagine why you would be boring if you are communicating honestly and tactfully. Perhaps your being too hard on yourself. If this is a pattern consider seeing a mental health professional who could help you come to a more understanding view of yourself in addition to helping learning how to communicate clearly. Best wishes.