You can't choose happiness. You just can't. I can't
wake up one morning and say "I'm going to be really happy
today!" and have it happen. You can ignore your sadness,
anger, depression, etc.. but ignoring the problem doesn't make
you happy. That makes you fake happy. You're not genuinely
happy. Deep down inside you're just as unhappy as you were
before, and guess what? The only way to change that is to either
wait it out, because sometines that's all you need, or seek
help (from friends, famiy, or professional). I'm sorry, but
it's true. You can't choose how you really feel.