Realize that we are all blessed to be alive and you should live each day to the fullest no matter what. Also, if you have extra stress, take a walk in the park, or even join a gym. Spend time with friends and family.
Think back to times you've worried in the past or been stressed out about something petty. Look at the outcomes of those circumstances and weigh their impact in the "grand scheme" of your life. Once you realize they're not a big deal, it's easier not to worry.
It does depend on what you are worrying about, but you do have to take action to resolve issues in your life does not matter how small. Your the only one that has to take hold of the reins and do something positive.