The Feeling of 'Saying Goodbye to "Me"' Each Winter...

I define myself as an optimistic, happy, easily-amused, and joyous individual. Someone who laughs easily and smiles often. And when the depression hits - I have this perception that I say goodbye to all of that because it all becomes suddenly so difficult to maintain. I become more negative, pessimistic, sad and apathetic, emotionally-drained. Happiness suddenly takes effort. Joy isn't my default mood anymore. I feel like I say goodbye to my happy self to make room for my depressed self. Or alternately - actually, more accurately, like I'm waving goodbye to my happy, summer self as a train/boat/car/bus takes me away and travels to winter. And as my happy self gets smaller in the distance, I feel empty and cold and alone and vulnerable. And into that shell of me creeps the depression, growing ever stronger as I approach winter (the train's/boat's/car's/bus's destination). Like an extended period of that sadness that comes when you have to leave summer camp...knowing you'll get to return next year, but feeling like there's an eternity to pass by until you get to return.