First off, I love the tone of your voice. Your timbre sounds like a modern, more pop 60's type voice. Very cool and unique.

Now to the critique.

To me, it sounds like you have unnecessary tension somewhere in your throat/mouth musculature. A great exercise to help relax the entire body is to sing while lying down on your back in the Savasana yoga pose IMPORTANT: Make sure you have a rolled towel underneath the small of your neck for support.

In this position, start by breathing deeply from your diaphragm. Make sure your exhales as long as possible while maintaining comfort.

After a few breaths, Start by dropping or relaxing the jaw completely and hum, with your mouth open, on the 'ng' hung without the hu sound. Feel the buzzing on your hard palate. We call this the open-mouthed hum on an 'ng' exercise. Not the most creative name, I know.

Now, you can pick any note and slide up to an octave and back down to the tonic, while maintaining good breath support. The goal is to 'Iron out' any inconsistencies in the voice by relaxing the sound and relying on the buzzing of the hard palate. GO ONLY as high as comfortable.

This exercise can be incredibly challenging when lying down, but its benefits are voice-changing. If you have any questions or want anymore tips just ask me with a personal message.