The key is balance
There’s almost never anything to be gained by becoming too emotionally involved. Having emotions is part of the deal, but they don’t exactly help you think rationally.
At the same time, letting your reason call the shots 100% of the time isn’t going to cut it. Emotions need an outlet. They can’t be controlled by suppressing them, and ignoring them will only make things worse in the long run.
You have to find the right balance. The right outlet, for both your emotional and rational selves. Direct them each into the areas where they can be the most productive. Make sure they’re both getting enough of a chance to express themselves. After that, you can rest.