Dear Lin Tan,
nobody can happy all the time,sometimes something can affect our feelings such as did badly in a exam,no friends to talk or have some problem with your parents and so on.have these feelings are normal,but,we can"t unhappy all the time,because it"s bad for our healthy,so,to solve these unhappy feelings is an important to us.there is som suggestions of mine:
1:when you feeling unhappy,you can do something make you have no time to think it.
2:you can also do something you like to forget that bad mood.
3:if you want to cry,you can sing or shout at a nobody room,then,you will feel muce better.
4:relax yourself,such as do some exercise,play sport,read or run.
5:talk to your close friends,tell them what do you think,share your thought,from your close friends,you can kown that happy is best important.
hope you will happy again
yours xx