That's because you raised your breath and throat. When you sing high notes, your breath will sink. That is, take a deep breath Inhale into the abdomen. Take a few deep breaths before singing. Don't sing high notes directly from the beginning. It feels like you're not making a sound in your throat, but moving it into your stomach. Which means your breath sinks. Knowing that your breath sinks first, the treble will go up easily. Or practice skipping rope. Domoso (mostly high notes) Somiedo. ..

Hehe ... I hope it helps you.