Start a kindness log.
In moments of anger or sadness, you might be scrambling to find evidence that there is kindness in this world. Your recency bias robs you of the memories and moments where you clearly have been the recipient of others’ kindness towards you.
In the moment, it is so easy to give in to the urge to feel like people are being difficult towards you conveniently neglecting that many people at many times have cherished you and acted kindly towards you.
This is the hardest part about mindfulness.
Remembering it. Retrieving it when you need it most. In the moment.
One potential solution to this could be maintaining a record/daily log of sorts and documenting those key kind moments that others have bestowed upon you.
You can then return to this log during moments of frustration to catch a break from the un-ending draining thoughts of negativity/anger.
Alternatively, your log can also keep track of the good deeds you have done daily. This forces you to remember your identity as a compassionate being and not someone who gives into evolutionary instinct of retaliation.
Here’s one template you may use.
I also found this public record of random acts of kindness quite interesting. Man, the world is a beautiful place filled with many people willing to help others if you are willing to look in that direction.