Left a longer comment in another reply, but to focus on how you feel emotionally - as a sole dev also doing support, you're a lot closer to the product than a s

Left a longer comment in another reply, but to focus on how you feel emotionally - as a sole dev also doing support, you're a lot closer to the product than a service rep typically is. It's something you created; of course it feels personal, because it is! The detachment that can help - but not remove - that emotional response is to try to change who you represent before you pick up the phone, as much as you can. When you're developing software, you're representing yourself, more specifically your ideas, plans, and execution. The software is a reflection of how you work. When you're supporting customers, you're representing the customer. This means the software isn't yours anymore - it's someone else's, something the person you're representing has spent money on but is now in your ear telling you they aren't getting the value they expected. If you can turn your viewpoint in that direction even a little - roleplay it, change your voice, give yourself an alias, literally put on a different hat, anything that can trick your brain into detaching yourself from your "normal" dev role and emotional attachment - the stress changes. It doesn't go away, it can't, because you're still YOU. But instead of taking the customer's WORDS as personally, you start to take the customer's PROBLEMS personally. And that doesn't sound like much, but it's an important shift from the problem making you feel SAD to the problem making you feel FRUSTRATED. It's hard to get past being sad because someone hurt your feelings. It's still hard, but less so, to identify a problem that makes you frustrated, because you can solve problems. You're a developer - you're an engineer, at least on some level. If you can identify a problem, you can solve it, which turns that frustration into motivation. (That sounds cheesy but I can't find less cheesy words right now, I'm pre-coffee.)