Very nice song, but harmonically it's a bit boring. If you do not leave the Bm-G axis, your harmonies become static (there will be no real change in harmony). Although it's fine for the first 4 rows of your melody, I expect a change in the beginning of the 5th row ("I know you..."), for eg. a D major chord would be logical since your melody uses f# and d notes frequently. To make things more interesting you can replace G major with its relative minor (E minor), when you feel it sounds good and fits your melody.
A long static section (first 4 rows) also would serve as a preparation for something special. I mean I expect a melodically much more interesting material from the last three (5th-7th) rows after the long and harmonically static "intro". This can be easily done by for eg. singing on a higher pitch and altering the melody a bit (or replacing with a new melodic part).
Btw. the lyrics are self-written? I like it.
PS. If you like your song as it is, just easily ignore my comments.
