We can't comapre this with mood swings. beacuse the situation you are going through is emotionaly unstablity but you should take care of yourself when it hits you mentally.
we all know some of the things dont go through the way we expected. Sometimes we have many things in our mind to share, but fail with the fearfull reason that is ,they would hurt or what if they become judgemental towards you??.and ends up by sitting silently with lump in throat and watching intensively in one dark deep direction with empty mind. but but but don't you think this is wrong??if you are with them in their high & low time then or you always cheer up in their "conflicts" then why you think that they would hurt, JUST DO ONE THING that is express your heart out this costs nothing. and still you feel like you can't do this then sit with him in silent for while,.