I am thinking too this might be some depression. I have difficulty myself with losing confidence and getting depressed. As hard as it may sound, try to get yourself outside even for just a few minutes. Isolation tends to make us feel worse.

I have a sense of this too right now. two weeks ago I was pretty pumped with confidence and even applied and interviewed several times for a job. Now I have not heard back and I am feeling a total lack of confidence as a result. My boyfriend has observed this and thanks to him, he has gotten me outside and doing some things. He had to drag me to a parade last night but I ended up enjoying it. I feel vastly better today and I am sure you will too if you can manage to get up and out where you are likely not to ruminate for a while.