I really like the Chopra Centre's definition of stress: stress is how we respond to not having our needs met.
Our need could be for a good night's sleep, a meal, warm clothes or someone to listen to you.
How do you respond to not having your needs met? Make a list of your unmet needs. List every event that contributed to not having having your needs met and start tapping on them. If you find it difficult to be specific at first, start tapping generally on an unmet need, and see what comes up.