I think what's making it harder is knowing that your ex has moved on. You've had this person in your life for 9 years, and to suddenly be without anyone must feel like a whole new world, and a scary one.
The best thing you can do is embrace your singledom....seriously. Revel in all the things you can do because you're single (not the things you would be doing if you weren't). You can be whoever you want. You can date anyone you want, you could date two or three people! You can eat whatever you want, watch whatever sappy girly movies men hate that you feel like. There are many things even I miss about being single!! Look at it as a discovery phase. Feel happy for your ex, but most importantly feel happy for yourself. You've shed yourself of a relationship you didn't want anymore and that's a big accomplishment....some people don't have the guts to do it, they just stay together and stay miserable. You have a shot at real happiness if you'd just appreciate everything you are blessed with in your life now.
Live as if you were to die tomorrow. Learn as if you were to live forever. - Mohandas Gandhi