It's important to respond with empathy and support, even if you feel overwhelmed. Here’s a suggestion for how you might reply:
"Hey, I'm really sorry to hear that you're feeling this way. I wish I could be more helpful right now. I care about you and want you to know that it's okay to feel overwhelmed. Please consider talking to someone who can support you, like a trusted adult or a counselor. You don't have to go through this alone. I'm here for you when I'm able, and I'm sending you lots of strength."
It's okay to express your limitations, but try to affirm your willingness to be there for them when you can.