There are two types of stressful situations: situations you can稚 control, and ones you can at least do something about to improve the situation. First figure out what is causing you to feel agitated and if it is something you can or cannot influence.
Is the stressful situation caused by circumstances you can稚 control? If it is, remind yourself you can cope with whatever happens, if indeed it happens. Now is the time to take care of yourself as best you can. If possible, remove yourself from the stressful environment. It may be that relatives are arguing, for example, and you can step away from this situation and find a more peaceful, nurturing environment. Take several slow, deep breaths, and perhaps even meditate or listen to a relaxation tape. Find distractions that are nurturing to you and healthy for you. You might for example, spend time with your pets, go for a long walk outdoors, take a soothing bath, or do something creative like paint, play music, or work in your garden. Gently bring your thoughts away from what you cannot control, to things you can control.
Is the stressful situation about things you can or need to do something about? Take a few, very deep breaths and try to relax your shoulders. Remind yourself you are a capable person and you can only do your best. When you are stressed about something you need to do, the best way to relieve stress is to take some action immediately. Often, the situation is very overwhelming, or you would not be feeling stressed. You may have doubts you can accomplish what you need to do. This is why it is important you remind yourself you can only do your best and that you will try. Procrastination is a common reaction, but that only increases stress and worry. Try to distract yourself from thoughts of negative possibilities. It helps to break the task down until you are only looking at the first little bit ahead of you. If, for example, doing your taxes is making you feel anxious, make your first task just to gather your materials together on the table or desk where you will be working. You will feel some relief as you begin. Then, you might just fill out the top part of the form. Take breaks as you need to, but keep returning to it when you find you are worrying. In this way you can break down any task into more manageable bites. Praise yourself and reassure yourself each step of the way and give yourself rewards for what you accomplish.
Everyone has situations they must deal with that are stressful. Find a healthy balance between dealing with what you must and giving yourself situations that make you feel good. Too much avoidance will increase your stress, but so will pushing yourself too hard, so switch between the two in a balance that is right for you, and always be kind to yourself. Try some of the above tips and advice and watch the calm come into your life.