Have you seen the sun recently, is what I mean.
Are you alone in a "world" of sad people?
Is it coming from you? When you wake up in the morning before you do anything how do you feel, before you have started thinking about anyone or anything.
If its them I would mentally gear up every time I had to be around others. One kind soul (in this forum) told me to ground myself by using imagery of a dragons tail, it really works for me. Also, rose quartz for love. Use obsidian for protection and grounding and transformation of negative energy in the environment. However be aware that it is known to bring up your own stuff in a very clear and blunt fashion.
Eat before you have to be around the gloom, take a walk in the sun and eat very fresh fruits and veggies. The ancients and enlightened often warned against eating meat that was always afraid and sad during life as it carries that energy in it's cells and is subtly passed on through eating it.
If its you, you will have to take better care of you and make sure you have fun, you might want to get a "happy" light to brighten up the darker, cooler months. A good friend who really loves you no matter what would be really great too. That kind of energy is so helpful to all of us. :hi:
http://www.google.com/search?client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial_s&hl=en&q=happy+light&btnG=Google+Search