THINK ABOUT 1 THING AT THE TIME
Your mind can only deal with one thing at a time and if you introduce more that two goals to you mind, you will surely end up feeling stressed. The only reason large projects seem stressful is because you try to think of everything you would need to accomplish at once. You should divide a large project or problem into small steps and execute those steps one at a time. This will make you more productive and you will not feel overwhelmed, therefore you will avoid getting stressed.
Remember.... how do you eat an elephant?? One bit at the time!!!