Really feel for you OP.
I know it’s hard but try to put everything out of your mind until after your interview. Laser focus on that. Tell yourself several times a day how good you are at the job. How clever you are. How loyal. How attractive. Keep telling yourself. Out loud. Believe me, it really does work.
Your goal now is building your own, financially independent life, where you have a great career, whatever happens. Tell your DH you’re blocking him for a week while you take some time. That way, he won’t distract you while your focus on the interview. And don’t put too much pressure on yourself about the job. Focus on doing your best. Thinking about what they’re looking for and showing you have that. That’s the best you can do. If you don’t get this job, it’s a practice run for the next one. But I bet you will get it.
As for your DH, how do you feel about him? Do you want to stay with him and keep the family together. Is he usually a good partner to you? Only you know how much you want to save your marriage. Only you know if you could ever trust him again.
But whatever happens, he’s the one who’d have to fight to save it. Not you. He’s betrayed your trust. He’s had a very inappropriate relationship with a teenager. He’s left his kids. He humiliated you. If you did decide to stay with him, he has a lot of hard work ahead to get his shit together, make it up to you and rebuild trust.
If you decide you don’t want to save the relationship, you’ll be fine. But see a solicitor as soon as you can to get ahead of your DH in the divorce.
You’ve got this. You’re strong and fabulous 💐