Speaking of birthdays, mine was yesterday (January 26).
A tone of relaxation and satisfaction with life's simple pleasures, a sense of ease throughout the first part. The feeling of comfort, reinforced by a hug, a special dinner, a cat sitting pleasantly in front of you, probably purring, and then telling you it's time for bed. All inside a warm home on a cold day. And It's your birthday, one of the ultimate measures of time.
Then there's a shift in the second part, from ease to a feeling of "I'd like to think..." and that time is moving "against my will."
Then ambiguity of feeling, a swing between "happy to be alive" and ... and what?
But then ending hopefully and positively, with an emphasis on "new life."
The kind of thoughts, sentiments, that we all feel on this subject, and which you have captured quite well.
Good job!
Oh, and your subject brought to mind the memory of an old 60's psychedelic song that would seem to fit and be appropriate for the present discussion:
https://www.youtube.com/watch?v=9hvj0hs7uj8