Hey, I know this sounds kinda obvious, but honestly, the more you focus on just being yourself, taking care of yourself, having fun, and enjoying life, the less and less you'll worry about Hannah, and eventually, you'll realize that your feelings have changed. Who we are and what we want in this life are two things which are constantly evolving as we grow. I'll admit, I spent almost 3 years letting myself suffer over one particular girl who I allowed myself to fall in love with. When I finally got past that, I was much happier, and not much more than 6 months later, I was already dating someone else and had mostly forgotten about my old feelings.
Heck, just tonight, the woman I was dating and I put an end to the dating side of our relationship. We're still great friends, and we intend to keep it as such.

We both realized that we're still trying to identify exactly what we're after, and that we just function better together as friends. She's 25, I'm 22. (yes, I tend to date older women... have always preferred things that way) Its incredible just how much weight has been lifted from my shoulders... as I'd been stressing about how to talk to her about this for several weeks. She called me out of the blue and admitted that she felt we made better friends than lovers, and I almost couldn't contain just how glad I was to be able to share that feeling.
Give it time (a few weeks or months might not do it... sometimes it literally takes years) and you will find that there are a LOT more women out there, and that a good number of them make a great, if not better, match than you have with anyone prior. Good luck
