A somewhat negative post perhaps, however this information was very useful to me in the last couple of months, when I had to deal with a lot of negativity, and a few negative people. Below is my summary of the strategies you could use to deal with someone who pisses you off. And I found a list of anti-depression herbs (my GP advised to get the same when I went complaining on stress), which could be used if nothing else helps, or in parallel.
Finally, remember, negative people are the ones you need to clutch in your hugs and not let them go until they stop yelling at you 🙂 Very, very hard to do.

Strategies to deal with someone who pisses you off:
– every time you interact with them, imagine they are dying
– every time you interact with them, imagine they are Buddha
– find 10 positive things in them that you are grateful for
– remember the changing nature of all things
– appreciate that qualities most annoying you are the ones you possess
– zoom in on the details of the person (eg their eyes) to realise your feelings towards their parts, and hence them as a whole, are neutral
There are meditations on all of the above, eg search for ‘meditation on changing nature of things’, which will further help you. But in the quote above, they summed it well – do not keep such people in your life. Totally. This is why I chose to leave the unhealthy environment I was in, in the end 🙂