Thank you for your query.
This could be mainly because you have been working continuously without a break.It could also be due to lack of timely food and lack of regular sleep.
Spare sometime for your self.
Right kind of food and proper sleep will help in reducing your frustration and dizziness
Take regular breaks in between your work by walking around or doing breathing exercises.If you are interested in music, listen to soothing music, or have a small chat with your colleague or friend. All of this will help you relax and do your work more effectively.
Take a break from work by going for a vacation.
would improve your concentration as well keep you mentally fit.
Try not to over commit yourself with any of your work.
Try having a balanced schedule.
For an immediate relief the best way is keep quiet for sometime by closing your eyes and taking deep breathes for 5 mints.This will energize you as well as reduce your tension.