If you are in a funk, it means that you are in a bad, unhappy mood and you don't feel like doing much of anything.

funk is a slang term that initally meant smelly. "Oh that chicken is funky" "How old is that?" That is the funkiest smelling thing....." It also refers to a genre of music that promotes grooving (staying in a repeating pattern). So when it applies here it is a combination of the bad implications of something funky (doesn't smell too good, it's a little off), and the idea of a ryhtmic cycle that is hard to break out of. It means you woke up and are kind of not feeling good (similar to waking up with the blues), or it means you are kind of in a slump. I keep trying to kick the soccer ball, but I am not getting it (I'm in a funk). It's like bad luck. A funk is a period of non success or something you want to break out of. It's an excuse. It's really idiomatic, and a ridiculously culturally specific piece of slang, so I hope I explained it well. Does it make a bit of sense now? It's a repeating pattern often with bad implications. The opposite is to say I"m in a groove, which is positive, a repeating pattern of success. http://www.youtube.com/watch?v=dGoRusmVCTk