I read this somewhere and it really helped.
The person who put the most in to a relationship is the person with the most to lose.
That hit me right between the eyes. The reason it was so hard for me to leave was the same reason that I was so angry. "I put so much into this, can't you give just a little?" Of course the answer (actions not words) was no.
Once I got that understanding moving on was much easier.
Your friend,
Once