It's bitter, but let's make lemonade. Embrace it as the fuel to drive whatever actions seem necessary and possible to you.
Take care of that light which lets you see how hate is no good, although, maybe you can yield it as a shield to brace the storm head on.
We could get philosophical about who that 'you' or 'your soul' is, which feels like being destroyed, and wether it really is. On one hand, this entity will still remain. Though not unchanged. But isn't that a good thing? I prefer being capable of feeling pain, as it sometimes just plainly is a totally appropriate reaction or sensation. I know that feeling of breaking, but on the other hand, if I could not feel that anymore, I surely was already broken. Dull and unmoved. So in a paradoxical sense, it is an affirmation that you are fine, a fine person.
Nations don't cooperate/conflict over how many similarities they have (although that makes things easier), but over how much their interests are aligned. It is well possible for two genocidal empires to oppose as adversaries, e.g. Nazi Germany and Soviet Union, the latter being proud of stopping the former.
Another example, colonizing empires fighting over their colonies. Neither did so to free the colony of the oppressor, but to become/remain that oppressor. You can imagine these empires as much the same as you like, they can still have conflicting interests (as in who rules the colony, not wether anyone should) resulting in fights up to World Wars.
How would that have helped them, apart from moral feelings? How many tanks, artillery systems, intel or even humanitarian aid would that have provided? Aren't the proposed countries more receivers of such things than donors?