1) Your H wasn't JUST a MLC, although the triggers of MILs death and daughter's accident certainly didn't help. But he was already in an affair at that time, AND he had previously had another affair with your "good" friend (some friend!). So really, he's a serial cheater with a character problem. A GOOD man who had just accidentally fallen into a MLC affair, would have at least made an effort to help more with daughter. I'm betting that if you really think about it, you'll find other past red flags about his selfishness, or possible hints of other affairs or inappropriate behavior on his part.
2) In any case, if there IS a chance of him coming home (there may not be) - but if there IS, he's much more likely to come home if he sees you GOING ON WITH YOUR LIFE. Get fit, date, be a happy healthy success in your own life. Don't put your life on hold. If he shows back up in a year (or two, or ten), you can decide then if he's worthy of the new you.
3) Don't take everything he says at face value. Lots of exes say they want you to date - that doesn't always mean they won't feel the pangs of jealousy once they see you with someone new. But at this point in time, that would be a GOOD thing.
4) BTW, MLC depression or no, your ex is a pig for not stepping up to the plate for your daughter.
