If you chase him, he'll run. The more you hold on tightly the more he'll try to break loose.
Here's an experiment....
For the next 2 weeks:
1. Stop chasing/pursuing. Don't text/email/call him as much. Only communicate about absolutely necessary matters: finances, children, etc. Your decreased initiative will get his attention. As you take off the pressure, he'll be able to think more clearly. Let him initiate the conversations. Give him space to think.
2. Don't talk about your relationship unless he brings it up. Stop trying to convice him to get back into the marriage. When he does talk about it, dont try to argue or prove him wrong. Just validate what he's feeling and listen.
3. Do something for you. They call it getting a life. Enjoy your life again. He won't be attracted to a needy, sad, desperate women. Join a gym, take Karate, take Yoga, take up painting, start going to church etc. IF you are strong and confident and attractive, he'll notice.