Do you drink diet soda or use artificial sweeteners in your coffee, etc.? Aspartame reduces seratonin production and has been linked to a variety of symptoms like yours including memory loss, mood swings, inability to concentrate, etc.
Check out http://www.mercola.com/article/aspartame/index.htm
Best wishes.
No i don't drink soda or coffee.
I heard it could be because i don't get enough iron in my diet.
Thank you for your comment!