This one is a tough one... It was real at one time. Sometimes people love other people the best way they know how - she just didn't have what it takes to sustain a M. It is a little like asking a blind person to see - just can't do it...
This all happened so suddenly and you may still be in shock. Pontificate - do what you need to do. Bounce around emotionally - that is normal. You have posted what is in your head. It will take time to travel from your head to your heart.
I am sorry there is no shortcut... There will be a bit of a void as you transition from your old life to your new one. You are right - you will get there. It is a little strange to think about it now - but there will come a time when all that you will feel towards her is a calm quiet indifference. I wish you didn't work in the same place - that makes it harder.
