It's not your outside influences that got you down... It's whats going on inside your body.
Vitamin D deficiency: Now for those of you unfamiliar with this, it is a nutrition problem that causes depression. Vitamin D is created in your skin when it comes in contact with direct sunlight. Its incredibly hard to get adequate amounts into your diet and during the cold season your bodies not getting enough of it. Its an endorphin, and a deficiency can leave you feeling like life is passing you by, but its not enough to motivate you to have fun, just enough to dwell on it, attracting large amounts of negative energy to surround your body and make yourself and those around you feel down. (well get into the energy thing in another post)
Build up of toxins- Processed foods, cigarettes/drugs/alcohol and lack of exercize leaves your body loaded with fatigue inducing toxins. Its hard to get the exercise in when the weathers so crappy, but there are ways around that. Take a minute to grab a piece of paper and write down reminders to get your heart pumping. (the constant visual stimulation will reach your subconscious) Doesn't need to be a half hour of muscle training or anything like that, go just five minutes of dancing to uppity music until you feel your heart pumping then rest, then do it again (the first time will be hardest if you haven't done that, as your unused muscles tend to get a lactic acid build up) find a buddy to go on fast paced walks with you, do 20 jumping jacks randomly, make it habit to do that thirty minutes after a meal, and remember after the first unpleasant energy burst your body will get warmed up and it will be smooth sailing after that.
Poistive energy- Kindness produces that bioelectromagnetic energy that surrounds you and can be sensed by those around you. Imagine doing a kind deed, think of things you are greateful for (like being able to see the color purple, getting to meet the most amazin people you have met, being one of the small percentage of people in the world with food and shelter at all times etc.) I think you'll find these thoughts to be soothing and they will attract positive energy to you.
Watch this video and you'll have everything you've ever wanted... "The Secret"