Brain fog after lots of stress and now i can't handle the stress and every little thing seems overwhelming. i feel like i can't concentrate. depression?

Maybe: Depression and anxiety can both cause slowed or inefficient thinking, but other conditions can too. Simple things such as a lack of down time, sleep, hydration, and exercise can all contribute to "brain fog." more complicated conditions, such as hormonal problems or medication side effects can also be causes. Contact your medical doctor to clarify the diagnosis and get the right care you need.