Love: A weapon

Here i am writing this blog.. sick to my stomach from emotions rushing through my body.
I feel like my ex girlfriend could care less or not about me, even though she pretends to. And it hurts so bad to see her with another guy only 2 months after breaking up. I know i know, "Who cares dude, you're broken up"..
Yah, that may be the case, but i definitely didn't realize what i had while i was with her.
I had the whole world, a best friend, someone to help me with my struggles, a counselor, a part time chef, a killer singer, and also a comedian. No matter what, she could brighten up my day

While we were together, i took everything for granted.. and i would talk to other girls and flirt.. not realizing i was only hurting myself in the long run. Yah.. it was unfaithful.. but most of all.. it was STUPID of me. That's basically in a nutshell what drove us to split up. It was a rather mutual breakup, we are still friends.. but i am finding it incredibly hard to be friends with her, when i know she's completely into somebody else. Don't get me wrong, i'd love to be her best friend still cause she is an amazing person.. but it hurts so badly.

Am i wrong in feeling this?
Am i wrong in still wanting to be with her?
Should i try and move on?
What should i do?