Constant headache & stressed out feeling

I have been getting constant head ache throughout the day. I never feel fresh no matter how much hours of sleep I get. Also, I easily get stressed nowadays while working or studying. My patience level has gone down drastically. This is badly affecting my life and career. My concentration level is poor, which leads to incomplete task completion and mistakes which could be avoided in things I do. Also I feel disinterested in things which I should be doing. This has been going on for 2 years now. Need to get rid of this issue asap as it is affecting my career and overall life. I really do not know whether this issue is psychological or dur to some other deficiency. Please help me identify the root cause. Thanks.