MLCers tend to avoid people with illnesses and/or people near death because it reminds them of mortality. Oh, they may call or text to inquire how you are feeling, but many of them will not be there to support you.
How do you use to the techniques? Well, for starters, you need to keep the focus on you and your family. If and when he contacts you, be civil and/or pleasant. Listen to what he has to say and validate what he says. Do not argue w/him about things. If something doesn't sit well w/you, you can say "I'm sorry you feel that way" or "I'll have to get back to you later because I need to think about what you are saying". You can also tell him that you need to go and get off the phone. Keep conversations on safe topics such as the children, etc. Do not bring up the relationship or why he left. I would even venture to say that you don't bring up your own medical situation unless he asks. Do not ask a lot of questions...the more you listen, the more you'll be able to pick up on his thoughts and what he's doing. They do love to talk...so let him.
If he comes over, make sure you have something really delicious baking in the oven. The aroma will stay w/him after he's gone. You want to be his lighthouse in the storm and you can't be that if you are begging, pleading, talking relationship talks, etc. The more you push, the harder they pull away.
I don't know if you've been reading the threads here, but I would suggest you start doing so. There is a wealth of info in each of the threads. Continue to post your questions and please stick to one thread until you've reached 100 postings/replies. You can also change your Subject Line within a thread at any time.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.