Pop Song Analysis

I am not sure how correct this is.
Not even definite my chordal analysis is correct.
But based 0n my analysis, this song doesnt seem to follow the standard chord function of T - PD - D -T. Instead its introduction has more of T - D - PD - T.
I have a feeling my analysis has some mistakes. HELP!!
Its phase is rather standard with short short long for the introduction.

I was very confused what chordal function Bm should come under... i thought it felt more like a passing chord to help in progression..

Start of the Music journey

My first practice on the modal practice for writing first species counterpoint.