Hi FeelingSad,
You can cry it out, not by yourself, but cry in the presence of another person such as your mom, or your close friend.
Then talk it out to them, even if it doesn't make sense, you get out what's bothering you, and even though the person who listens probably won't get 100% of it, they're there to listen to you FeelingSad.
Listen to uplifting music, and sing along, and believe that one day these songs will fit perfectly to your mood. Have you heard of fireflies by Owl City?
And when you feel scared and alone, close your eyes and draw a mental image of all your loved ones walking beside you because they believe in you.
I believe you will make it through FeelingSad, hang in there.