"If it helps, try to remember that your perceptions are just illusions based on maximizing the effectiveness of your mating strategy and they are defunct in a modern world that does not reward protecting your sexual investments with a higher rate of impregnating them.
You can also remember that human beings are just huge sacks of wet fluids and oils with soft tissue around them which are so developmentally complex that they have forgotten that they're living things and have begun to see themselves as individual people, so, like, your girlfriend was just some fluid sac filled with eggs man. go get another one.
Also how about this one: human memory is incredibly shitty at remembering objective details but extremely good at remembering emotions. You're not actually remembering shit that happened, just how you felt about shit that happened. Maybe go make some more shit happen and feel good about that shit."