Is this why it feels like my W's goal in life is to torture me? I really don't understand the co-dependency angle. She already has my attention, why continue to push my buttons (torture me)? When I pursued, she tortured me. Now that I'm distancing, she is following me around to torture me. What is her goal? Did the book explain this? I want her to leave me alone, but she won't. She won't stop texting, she follows me to church every Sunday, she keeps the children on the phone with her when they're with me, etc... Is this her strange way of showing that she still loves me?
If it feels like torture then it is torture. She is torturing you.
If you'll permit me I'll rephrase your question: "Is she torturing me because she loves me?" The answer is, she is torturing you because she CAN and because she WANTS to. She is deriving a perverse satisfaction from torturing you. It is not love.
You ask:
Is this her strange way of showing that she still loves me?
No, it is her strange way of abusing you. Loving people do not play cruel mind games. Love is patient, love is kind. Is your W treating you with patient kindness?
It is difficult for you because the abuse is covert. Going to your church, texting a lot, keeping the kids on the phone during your time with them, doesn't sound like abuse to most people, so it leaves you confused, sometimes doubting your own sanity and doubting whether anyone would believe you are being tortured/emotionally abused.
You want her to leave you alone? If she does not respond agreeably to a polite request that she leave you alone then there may be no other way than to take evasive action.
Attend a different church. Change your mobile phone number so you can't receive texts from her or block her from texting if that is possible. If she needs to communicate with you regarding the children she can do so by a telephone call. You can choose whether or not to answer or she can leave a message to which reply to in your own time after having thought about what your most appropriate response will be.
Good luck.