I used to be a professional poker player and had to deal with controlling my temper a lot. Not an easy thing to do if you are born with a lot of it . Anyway what I did was tjat I red this book: https://upswingpoker.com/mindset-tips-improve-results/. It is for poker players but it covers real life aspects and teaches not to dwell on things you can`t control. For example standing in a long line in a shop and so on.

It teaches you how these unfortunate things just happen to everyone and how it does not just happen to you only. It had some really great tips to control your emotions so if you know anything about poker I would recommend reading it not to be good at poker but to learn how to control your temper and how to look at the big picture of things.