image from: Angela C
People have moods, rages, angers, tempers, low days, high days and so on and so forth and there is absolutely no work for you to do in such an instance other than to let them be.
Everyone is responsible for their own feelings, and if you have the misfortune of being in a close relationship with someone who carries the false belief that their emotions are the result of other people, then you will suffer the results of this false belief. If you too carry the false belief that another person's happiness or sadness can be in any way influenced by you - then you are putting yourself forward as a willing volunteer for emotional suffering.
Although at times it seems like there is a very strong link between what you do and how another reacts, and although it can be easy to conclude that you are the cause of that happiness or sadness, it is incorrect to take this link as a statement of belief. Yes, its possible to make a crying person smile, and its possible to make a smiling person cry - this does not mean you are impacting on their personal emotional health in any way.
Think of yourself when you are in a bad mood. Whilst it's true that a friend can make you laugh, and bring a short period of relief from that sadness - not a cure.
When someone is behaving in a way that begins to trigger fears and anxieties in you...STOP the thinking. You are getting sucked into a vacuum and you are absorbing their emotions. Walk away. Give space. Get yourself into a place of high mood, and work on letting the interaction go. Move on with your day, your week or your month and let the other person be.
There people who love peace and happiness and will continually seek them no matter what challenges fall in their way. Slow to get offended, slow to anger and slow to upset - forgive readily and easily and rush to make up after a conflict. Happy to see others happy, helpful, kind and willing.
There are also people who love drama and sadness, and will find it even in the happiest and most relaxed of days. They are quick to anger and irritation, quick to get offended and start a war, quick to upset and depression and bear a grudge over the tiniest of things for life, jealous, competitive and manipulative.
And there are also people who are somewhere in between those two points, having good days and bad days, short tempered days and relaxed days.
You cannot really have any impact on a person's mindset and way of understanding the world - so don't bother. A person who is determined to have internal peace will seek it relentlessly, just as a depressed person will seek sadness relentlessly.
Leave them be. And release yourself of all responsibility.