1. Understand others, therefore can describe them in a way suited to their way of thinking. This is probably controversial assumption but I believe people are unconstrained, everyone can understand everything, it may just require more time. If you believe people are constrained, or just don't want to spend time on them—find people who are capable of understanding you right away. By being honest about yourself you will attract like-minded people. The process of "explaining yourself" obligates you to approach new people (not only your current closest) and explain them your existence. If you feel understood only by your closest friends, then you are not good at expressing yourself.
2. become less self-concerned. You no longer seek validation and significance—you are fine with being normal. You no longer need someone who will make you less lonely, someone who will fix your flaws. You no longer focus on yourself (you know this guy good enough), rather, you pay all the attention to others, you become emphatic, which connects with others, and thus you become less lonely.
3. You can honesty communicate your needs, fears, desires, emotions. They are part of you, and hence it's your responsibility to explain them to others. Don't expect people to read your mind. Don't run away using abstractions, give concrete examples. If you believe in small lies for a greater good, then you are not communicating yourself. If you consider breaking up with your SO, talk about it with him/her, not your friends. If your boss annoys you, tell him which actions annoys you. It requires a lot of courage therefore little people do so, but not doing it results in loneliness. You have a choice.