some nice tonal qualities in your voice

Sounds like maybe you need to learn to release up into your headvoice. In other words when you were getting up into the higher notes (G4-Ab4 etc) that it started to get a little strained because you are probably trying to hit those notes using only chest voice.

are you familiar with the "passagio" etc? Your voice sounds like a standard voice where its more or less chest voice only. You need to learn to "bridge" up into thru the passagio to be able to sing up into higher phrases without a noticeable break or change in sounds etc.

if you try to do one long ascending note do you have to "flip" into falsetto at some point?

chest voice is basically very similar to your speaking voice. Then you have head voice which sometimes requires a bit of training to develop or "find".

You ever use falsetto? falsetto is a type of headvoice. if you can take your falsetto and learn to make it stronger 9make it vibrate more on the roof of your mouth etc) then you can learn to connect your chest voice to your head voice.

youtube has approximately 37 million vids on the subject lol

https://www.youtube.com/watch?v=HjmWXkBlS6E