You might want to have your thyroid checked out. It's a very simple blood test. If you already have a condition, it may be time to have your meds adjusted.

Other conditions to consider:
bipolar disorder
hormonal imbalance
situational depression

Look these up on the web and see if the other symptoms sound like you. I'm grasping at straws really, without knowing you. Good luck, and hope you feel "normal" again.