If you say; “I will be compassionate,” that is not enough. This is not a situation where you can say; “ok I will do it,” then it happens. It has to be based on a clear understanding of why and how it is so important.
When you have developed that understanding of the importance of compassion, why compassion is necessary, then maybe you arrive at a place where you have more clarity around what the choices are. If I am compassionate it will be like this, if I am not, it will be like that.
It is maybe more important, better, to really feel the necessity of being compassionate. That is the time you need to decide; “yes, this is right, I should really be compassionate.”