Cloe, if you think it's more than the blues, maybe you should see a doctor or counsellor? I'm not saying you are clinically depressed, but it's never a bad thing to have someone to turn to if your mood gets worse. I saw a doctor around January because I felt this way, and she said she thought I had a mild depression. I took care of it by following her advice as much as could and six months later, I feel so much better!
There is also something really simple you can do that can help you elevate your mood: exercise. It's not a quick fix, but it's been proven to help people suffering from depression. I've found that going to gym or walking/running in the park makes me feel more connected to the world even if I'm not directly interacting with anyone. My shrink recommends at least 30 minutes a day of exercising.
I feel for you
“Inside every cynical person, there is a disappointed idealist”--George Carlin