I'm taking a class on stress management right now, and part of what they talk about is how we train our minds over time in how to deal with stress. The more we do Reaction X, the more our mind gets used to doing that. So if we always snap at someone, we train our mind to snap in anger, and it just does that by default.
So to train our minds to do something else, we have to think about it deliberately for 30 days. We have to "retrain" our mind. Yes, it's hard to retrain a mind

. But after 30 days, our mind now has a new way it's used to doing and the new way is now its normal way. So it gets easier and easier as it goes. I.e. it'll be hard at first. But soon it gets easy.
So start with just one day. Just today. Just for today, your task is to be patient. Remember that life is 80 years long (or more) - nothing that happens today is that important. Take long, deep breaths. These help to relax you. If something gets you riled, count to ten. Then, before you answer, think, are you really going to care about this in ten years? This event, whatever it is, probably isn't that important in the grand scheme of things. Think about what IS important to you, like your health.
Let us know how it goes!