Depression

I feel like I may be sliding into a depression.  Not getting that job is really feeding my negative self image, and then all my other bad thoughts are like dessert.  I'm trying to stop, I can actually visualize digging my heels in, but I'm getting tired, and each day something else is added on to it.  I try and be thankful for all my blessings, and I have a lot, but that only helps for a short while.