Do you get outside every day? I go outside most days but sometimes I don't make it because I am so busy indoors. I always feel better after getting some sunshine, though.
Most of the time I stay indoors, but I always try to go out, breathe some fresh air and get some sunshine. Like you, getting some sunshine makes me feel better and helps boost my mind and mood.
I would go crazy too if I was stuck inside all day. I make sure I get outside every day! I even go outside when it's nasty out. The cool air helps open my sinuses up. I love being outside.