I'm sorry you had to deal with that- I don't want you to feel like you ever have to do that again. [That much is genuine sympathy on his part, even if he doesn't have all the context of what happened to Rue. He's relaxed under Rue's paw, even as he worries his bottom lip between his teeth.]

I'm just... supposed to be spider-man, I'm supposed to be strong and capable. I'm an Avenger, I went to space once. I'm not really good at being a superhero anymore, but, being upset about everything isn't useful...? I can't help anyone if I'm hung up on my feelings.

[For as much maturity as Peter does have, he's still a teenaged boy with a skewed idea of how to handle himself. His natural compassion is for everyone else but himself.]