A Different Kind of Sadness

Why am I so depressed?! Why do I get so depressed? I'm surrounded by a loving & supportive family and the best friends. Could it be hormonal? What triggers it? I can get pretty down... Our house can be filled with people laughing and having a good time, and I still feel lonely. Idk what's wrong with me. I am thankful for all I have and have been blessed with... #GodIsGood, I just don't know what's wrong with ME:'(