I am very glad you returned to post an update. I'm sorry to read that you've had bouts of depression over the last year and I do hope that you are feeling better soon. Are you taking AD's or seeing a therapist?
I can't believe how old your children are! Time sure does fly and I'm sorry your xh hasn't been supportive both money wise or physically, mentally or emotionally to you and the children. I hope and pray that some day he comes to realize what he's done. He's got two great kids that needed a father in their lives and yet, he elected to walk away and basically ignore them.
He'll be surprised when they send the repo man out to get the car...but that's on him. He needs to face the consequences of his actions and not paying his bills will continue to get him in hot water.
You are wise to keep the focus on you and your kids. NLW, things will change, but change takes time and it's slow...but slow is good to make sure you are happy w/the changes that are taking place in your life. Continue to take it one day at a time and don't look too far ahead...things tend to change very quickly when we do that.
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.