You sent this text to a friend who you noticed had been a bit low energy saying “I've noticed you've seemed a bit low energy lately, and I just wanted to check in on you. If there’s anything bothering you or if you’re going through a rough patch, I’m here

You could respond with something supportive and encouraging. Here’s a suggestion: "I'm really glad to hear you're starting to feel better! Just remember, it’s totally okay to have ups and downs. I'm here for you, and if you ever want to talk or hang out, I'm just a message away. You're not alone in this!" Feel free to customize it to match your style!