If you want to get him back then the best thing you can do for him is to back off and let his anxiety over the whole issue die down and let him contact you. Stop contacting him until he is ready to call you and the evil MIL isn't so upset.
You said it yourself he does not want to leave his children and you know he wants to see you. Right now however, he is inclined to push away from everybody and emotionally shut down even though we want to reach out, he can't. When he is ready, it may take a bit of confidence, but he will contact you. When he does he will need a lot of praise and support for the littlest things to help him out of his shell. All you CAN do is support him and listen to him when that happens with NO pressure to get him back.
It sounds to me like he has some serious problems that local herbs just won't fix, or for long in most people and the pressure from this situation caused a nervous breakdown so severe that he feared for his life and his mother had to take him in. I should know I have those problems and just had a severe panic attack and depressive all last week. Even though my wife called and called worried sick over me, I just couldn't talk to her and spent days in bed having manic depressive states. Then around Saturday I reached out to let her know I was ok and she helped me feel better. All I needed was time to myself.
You express concerns for the other woman meeting him at a time like this, but I ask of you... Has she seen him at times like this? Normally these severly insecure times turn off other women but the nurturer in you grows stronger and loves him more than she ever could.
