I met my soulmate just 2 months after I proposed to another woman

From a male reader

I proposed to a girlfriend in June 2015 and just two weeks ago, I ran into an ex, a lady I dated for a year about 9 years ago. I fell instantly inlove with her all over again and I have no doubt that she's my soulmate. The way we met again was divine and I believe this lady is the person I am meant to spend the rest of my life with. The only problem is I proposed to another woman two months ago who I gave a ring to.
I'm in my late 30s and I was eager to settle down and she seemed most suitable from the lot but now that I have found my rib, how do I break my engagement with my fiancee without breaking her heart? My new love doesn't even know I'm engaged. I am hoping she would even read this here and forgive me for not coming clean with her.