First of all pause to take a deep breath or a number of deep breaths. This will help to calm you down and think about the situation before you react so you won’t react in a way that you will regret later. It also gives you a moment to think about how you would like to proceed next when you are in a stressful situation. It will also help your heart and blood pressure slow down. I then feel more confident, happier, relaxed and better able to cope with the situation at hand.

Secondly, you can talk it out. You can either express your thoughts and then allow the other person to do the same. If you would rather not express your thoughts to other person that stressed you out or discuss the situation further, you can also talk to yourself out loud. You can make believe that the other person is listening and either agreeing or apologizing. The latter helps me the most to feel happier and more confident to have a better day.
Thirdly, you can listen to your favourite songs of the past or present. Listening to slower jazz music or my favourite love song usually puts me in a better mood pretty quickly. It helps to calm me down. It makes you feel happier, more relaxed, and self confident.
Fourthly, you can do something out of the ordinary or that you do as a routine. We usually have a certain schedule of things that we do. Try to break out of the monotonous schedule by doing something new and something that you don’t do very often. Take a dance class if you like dancing.
Take a sushi class if you like to eat sushi or want to learn about the delicacy of sushi making. Take a gardening class if you like to buy potted flowers that are changed seasonally.
Lastly, you can start a personal journal. You can write anything you want in them. You can write down the different things that happen to you throughout the day. You can write about the things that you are grateful for and that you accomplished. You can write down inspirationally quotes or favourite sayings. You can write whatever you want. I personally like to write down things that I accomplished like a success journal. I also like to write down inspirational quotes that will make my life better, motivate me when I am in a rut, or things that make me feel happier and more self confident. Lastly, I like to write down the things that I am grateful for. The latter is a reminder of how lucky I am.
There are so many other ways that also work but these are just 5 ways that I like to feel happier, more relaxed, and self confident