I finally found out the original song of the instrumental piece I have been listening to since forever!
I listen it in my office almost everyday (and I only play 2 songs on repeat) and nowadays I play it before I sleep cause it helps me sleep!
I listen to it when I have headaches too. and it helps. hahahaha.

but after listening to the original singing version. I still think the instrumental is nicer.
=D

Here's the original singing version:




Here's the instrumental version:

My Everything - Rachel Milstead