Your throat hurts when you sing most likely because you’re not breathing correctly and using your core to produce the sound. Many singers tend to sing from their throat. If you’re doing that, you’re mostly likely feeling strain. Other reasons could include, you’re extending beyond your normal range. It’s normal for your voice to feel tired but to have pain is a sign to stop and change what you’re doing because you don’t want to develop nodules. Another possible reason is because you did not warm up your voice. Not warming your voice is like not properly stretching and doing some cardio before you run a marathon. You’re not just using your vocal cords, but also your core, mind, body, and heart to sing your best.
To prevent vocal pain, I would highly recommend doing basic warm ups that are at least 10-15 min long. Warm up all parts of your range, activating your diaphragm breathing. You can apply the above exercises to warm up your voice on your lowest note to the highest note you sing comfortably. If you’re still experiencing pain, please work with a Vocal Coach. I’m happy to help you in my private and group vocal coaching sessions. Check out my offers here: https://linktr.ee/joanncchang