What i learned today in school!

In school today i was actaully paying attention and they were talking about people who are suicidal and the signs and i was like :OOOO they said signs that a person is about to commit suicide is if they were all depressed then out of no where there all happy and mood swings and lack of energy and start giving out their personal stuff away and getting bad grade and i was like :O i actally know some people like that!!!!!!!!!!!!!!! and i was like scared *-* i was like fuck is blah blah blah suicidal o.O and now im like .-----------. i feel scared like deep inside i feel like somethings going to happen help me?:'(