The world is populated by a wide variety of people, one species of which seems to have evolved solely to push our buttons and rub us up the wrong way.
It is easy to feel stressed out and irritated by the members of Difficultus Humanus; but dealing with difficult people can be done while keeping your cool and your integrity, and without becoming overwhelmed by stress.
I run stress management workshops, so I am pretty much in control of my own blood pressure, but that doesn't mean that I never get fed up with the way people behave. However, I know how to handle my response to difficult people, so that I don't let stress overwhelm me or ruin my day.
You can not control how other people think and behave, so the best thing you can do is learn to control your reactions and responses, so you can prevent them stressing you out.
You are allowed to feel a bit aggrieved and annoyed if people make your life difficult. The trick is to ensure you don't become ensnared in your own mood. If you let a difficult person ruin your entire day, you are letting them have control in your life. Why would you give a difficult person the reins to your fate?
We can decide what sort of day we have by what we choose to focus on. Do you want to give the difficult person all your attention and time, or would you prefer to focus on the people who make your life wonderful and worthwhile?
Additionally don't give the antagonist more power than they deserve by taking their attitude personally or creating a whole story around your relationship.
Your mother-in-law criticised you? Don't assume she hates you. Maybe she's just protective of her offspring. Your boss is demanding too much of you? Don't tell yourself your manager has it in for you. Consider that maybe they're overworked and under pressure too.
People's difficult behaviours are almost always about them and what's going on in their life, and not about you. You don't have to lose your own integrity by reacting in a rotten way.
With isolated incidents, remind yourself that it's the other person's problem and you don't need to react. If it's a repeated train of events, it may be time to gently assert yourself, and tell the other person how you are feeling.
Your approach is important here. People put their guard up when you attack them, and that means that they won't listen; so it's better to broach the issue of their attitude gently.
Use "I" statements to soften the blow. Rather than saying "You make make feel bad when...", say "I feel bad when you...". Rather than saying "You're a nightmare to work with", say "I've noticed you're on edge recently. Is everything OK?"
Remember that you have the right to feel however you feel. But you are in control of your reactions. A negative feeling is not who you are, it does not have to last and it doesn't have to affect your day. Choose not to let it.
Be the better person and do the right thing. Acknowledge your frustration, assert yourself if you need to, then move on. After all, you'll have bad karma if you sew prawns into their curtains...