Relationships and Sociology

Is this new chick a rebound? Prepare for a long wall of text. This is our history:
I've known him for 2 years prior to dating him for almost 2 years. We're both in our early 20's and we were each other's first love, first everything. We were deeply in love with each other and swore we were each other's soulmates. He changed my life and I changed his in various ways. I've never connected with someone so deeply before. We rarely connect with people like this so it was special for the both of...