Reminders, why won't he leave me alone?

i have been out of the emotionally abusive relationship for nearly a year now (after nearly fifteen) and it isn't any less exhausting.  Although I say I am free and refuse to engage the phone calls, texts, emails, and periodic drive by's continue.

clearly a certain aspect of our relationship must be maintained because we share a child, however I am trying very hard to keep it business like...reminding myself to ignore the name calling, not to bite after he spins off on a tangent and then sweetly apologizes and tries to make nonchalant conversation.  And when he tries to pull on my heart strings by reminding me of the few happy moments we had, they were "a few" trampled on by name calling, control, isolation, degradation, blame, hostility, an over abundance of unhappiness that largely outweighed those "few".

constant headaches, I hate to look at my phone.  

Will ll it ever stop?  When does it get easier?  When will I no longer have to tell myself what to do (because there is a piece of me that could respond, that could easily rubber band right back).

being where I am makes me feel guilty and ashamed, embarrassed, and stupid.  

I don't much like to look at myself anymore.