It's tough to want that love from the one person who doesn't feel it for us.
I read an article about what happens to the human brain when faced with rejection and it's very similiar to coming off drugs. Dopamine is a feel good chemical in our brains and when we are rejected by a lover, the dopamine levels drop significantly. So we try to look for another hit of dopamine by chasing after our walk-away spouse.
Keep putting one foot in front of the other. I've been told things will get easier with time...