If you are not taking ample sleep then your work will surely suffer. You will not be able to deal with your customers in a healthy manner. An average person must take a sound sleep of 8 hours. The next day you will feel fresh.
If you perform exercises and yoga on regular basis, there will be no or at least diminutive signs of stress. In fact you will be able to give an appropriate amount of time to personal and professional life.
Diet is another important factor which you should take proper care of. As the saying, Healthy Mind resides in a healthy Body, is appropriate for this. If your diet is good, you will decrease the odds of falling ill.
To perform your work in the best possible way and succeed in your life you should avoid stress. Stress taken to some extent i.e. in positive manner is good but if it exceeds in a negative way that will hamper your work.
You should talk to people, go for outings and avoid staying alone. Going out will let you know about to recent trends. You will meet new people and learn new things.
So I would like to suggest that you should do your work with maximum degree of awareness and relaxation but should keep the dead lines in consideration. Choosing your career as freelancer is a great idea if you can easily go with the deadlines in a casual way. Every person works hard in order to succeed but I personally think that success should not come on the cost of health. Such success would be useless as one works hard to live a happy and peaceful life. Success which comes on the price of health is of no use. So, keep a perfect balance between your health and success.