I think this was a 70's song.. but I'm not totally sure.. The rest of the lyrics I remember are " and I thought I'd die, but I didn't".

Hi Rikkirich - I found this section of a song called 'Is This All There Is', it was sung by Peggy Lee initially, but has been covered by quite a few artists. (this one says one day "he" went away, but I think this might be the song you're looking for?)
"I fell in love, with the most wonderful boy in the world.
We would take long walks by the river or just sit for hours gazing into each other's eyes.
We were so very much in love.
Then one day, he went away. And I thought I'd die -- but I didn't.
And when I didn't I said to myself, "Is that all there is to love?"

Thank you aliseaodo! That IS the song I was trying to remember! And it was the Peggy Lee version that I remember the best. Thanks for solving that one for me - it was really bothering me!

Yay! -