You pulling the trigger to switch the trolley to kill only the 1 person can and will have consequences on your own mental health.

That's called selfishness, and it's not generally considered a factor in ethics. At most, that changes the equation to 2 vs 5. Still easy.

unless you're a fucking psychopath, you're not gonna kill your newborn to save 5 strangers.

Then psychopaths are right and neurotypical people are wrong. The world would be better off if it had more psychopaths, as you describe them.

But you're wrong about psychopaths. See, what you're describing is limited empathy. You have more empathy for your baby than for five strangers, because of your limited point of view and inability to abstract the situation and see the bigger picture. A psychopath, according to pop psychology (psychopathy doesn't actually exist in serious psychology, but let's pretend it does) has no empathy. A psychopath doesn't care who dies. They probably save the baby because it's more socially acceptable and will make them look good. That's selfishness again.

If you want to know who saves the strangers, well that's someone who has empathy for both the baby and the strangers, and the wisdom to empathise equally with both. That kind of wisdom is extremely rare because natural selection doesn't favour it. It doesn't offer any advantage over the rest of the species to be that selfless. So you'd be most likely to find it in an extremely rare combination of autistic traits, or in a very enlightened Buddhist monk.