Why do I feel blah?

I was having a really great day until maybe 5 pm. Then things just sort of began to disintegrate. Calvin was fairly grumpy today because he's teething, but that didn't really bother me too much. The tree trimming guy quoted $$$$ to trim our 5 fruit trees (it was a fair quote, but it's just a lot of work and more $$$ than I thought), but I did OK w/that too. I was just sort of taking it all in stride. But then this afternoon I was VERY hungry and I was teaching so I just had to wait for dinner... and my piano students seemed more challenging than usual, probably because of Halloween, etc. So when I finally finished teaching and got to eat, I was moody and irritated and snapping at Loren and Calvin for no reason. Calvin didn't want to try the very delicious split pea soup I made, which made me irrationally annoyed. Loren pointed out that he's a baby and doesn't know that he needs to try different foods, which was very true. Anyway... so then I was still cleaning up when the ladies from the Bible study began to arrive. I had made some cupcakes, but frankly, they were terrible, and no one liked them, including me. So now I have some weird complex that everyone thinks I'm a terrible cook (which is totally absurd) and a lousy hostess, and I know it's not true, but I'm in this bizarre funk, so I can't stop thinking ridiculous thoughts. I guess I was feeling this way a bit last night too. I'm not sure what the deal is, but it's annoying and I want it to GO AWAY. Usually I don't feel so insecure, but lately, I am just a basket case. Why? What is going on? So, if you read this and you're a praying person, please pray that I'll snap out of it or something. It's very self-absorbed and icky. Thanks in advance.