Having low self-esteem and many worries about how others view you might make sharing parts of yourself seem unthinkable. Remind yourself that even if you are preoccupied with yourself, maybe even sick of thinking about yourself, people in your life experience the opposite. As a shy person, people you care about may be wishing that they know or understand you better. By making attempts to let some of this inner-world out, you are also opening yourself up to other perspectives. If your self-image is quite negative, chances are good that opening up to those you trust will only help you see great parts of you that you fail to consider. When you want to open up to friends, family, or a romantic partner, don't be afraid to be frank about where you're coming from. By letting your guard down and talking about how you presently feel, others will feel instantly connected to a deeper part of you. Most importantly, the other person will not recoil in doubt or fear that something wrong with him makes it difficult for you to open up.  Try starting with something like "I want you to know that I'm a little shy talking about this, so please bear with me." This statement enlists support rather than making an excuse. Remember that you do not need to apologize for your level of progress in opening up. Apologizing will set off doubt and passivity. Make sure that you are not owning your shyness to signal that you need sympathy or babying. The purpose is to give insight into why you might seem nervous or aloof. Having patience and support from others should ultimately help you take risks and display effort as you learn how to be more comfortable opening up. Turn your focus outward and let the other person motivate your desire to open up. Watch facial expressions and listen for raises in tone that cue you in to what the person is getting excited about. Excitement is contagious, and with deep engagement it'll be hard not to return it.  Deep attention to the cues of others does not mean that you should take a subordinate position in...

TL;DR in Indonesian:
Izinkan diri Anda berbagi. Akuilah bahwa Anda memang pemalu. Berfokuslah pada lawan bicara Anda. Ungkapkan isi hati Anda.