Do what I've done, I found males (within my family and husbands of close friends) to become a strong, male presence my kids need. This is not the same as a father being present but it does show my children what a healthy man looks like.
My WH also vacillates between mean and friendly, what I've done is kept our convos strictly to the kids and nothing else. If he is rude I call him on it in a quiet but firm manner. I tell him to speak to me with the same courtesy he uses with his patients. I told him on no uncertain terms that I would no longer tolerate him being rude to me and would limit our interactions to ParentTalk app if he snapped at me again. Seems to have worked for the moment.
I've started realizing that I DON'T want my WH back like this. Unless he has a Come To Jesus moment and does extensive introspection I do not want him in our lives. My WH is on meds for ADHD and he still has no done the hard work of looking at himself and making changes. He is in arrested development and there has not been enough of hitting the bottom for him to change. I cannot let this weight be tied around my family's neck. He is an albatross and will pull us all under unless I show the strength to cast him off.
Cast him off, move forward. If he does not make changes then at least he will not damage you and your child any longer. This is hard, possibly the hardest thing you will ever do. So far you've made tremendous strides and taken control of your side of the street. Don't tell him about your consult jobs, your positive changes, your negative changes. He no longer has the privilege of your intimate life. Stay distant and mysterious.
M 10yrs T 13yrs BD #1Oct 2015-PA between WAH and COW BD #2 April 2016-WH resumed PA, she broke it off Jan 2 2017 WH says he wants divorce April '17-Letting go 2018 D busted DD8, DS6, DS3