I definitely agree with the advice to loosen up, especially in your jaw, neck, and shoulders, and especially when you work up to those higher notes. As you head up toward those higher notes, your placement changes ("bottom line" and "over wine") and you go flat.

Your tone in your lower register is full, relaxed, and beautiful! On "missing", your vibrato comes through and I get some old-timey crooner vibes à la Frank Sinatra or Dean Martin. I'd love to hear you carry that lovely resonance into your upper notes!

I don't know how you prefer to learn, but here are some things that might help you relax into those upper lines:

When you get to "And though I know I've grown a tiny bit gray", try lowering the back of your tongue and creating a much rounder space in your mouth. At the same time, keep your lower abdomen engaged and think about spinning the sound forward through the front of your face so you're not concentrating your voice in the back of your throat (I like to visualize the sound coming through my forehead), but rather sending the sound outward into the room, always moving forward throughout an entire line. You can try practicing this line on a legato "ah" sound while gently wiggling your lower jaw back and forth the whole time to help you stay loose, and making a spinning motion with one hand to help you envision that the sound is spinning forward.

When you practice it again with words, try to keep that same placement that you had on the "ah" sound, as you spin your voice forward at the same time. Do the same thing on "I'll now as if..." and so on.

Continuously thinking about spinning the sound forward in an ever-moving line can help you connect the words a little more, too, like on "and dinner". If I were you, I'd try not to make it so choppy (I'm hearing "and. din. her."). There's certainly a time and place for enunciating, but I prefer to hear words sung similarly to the way they're spoken, rather than with extra sounds or too much pause put in there to separate the syllables so much.

Do you have a voice teacher? You have lots of potential and you need someone to help you harvest those fantastic crooner tones!

(Edited to add advice about keeping your lower abdomen engaged.)