Lord, have mercy!
I am in the same boat, although for a different reason... I also experience an enormously hard time fitting in, but not because of the "crowd" at church being culturally, ethnically foreign - rather, because of my particular "crowd" (family and friends) being non-believers, philosophers-sceptics of various sorts.
The only advice I think I can give, based on my own experience - just live one day at a time. If you have serious seasonal affective disorder, see a physician and take a medicine (that is extremely important - you don't want that serotonin to escape from your brain synapses!!!). Read good books, watch good movies, avoid negative or quarrelsome people. God will take care of the rest!