I don’t think it’s a good idea to have same individual and couples therapist. It doesn’t seem right but who knows. Your t maybe defends your husband because of whatever he tells t in private. Maybe things about you

I think the issue isn’t if he is always going to behave nicely but lack of foundation in the marriage. Like it shouldn’t be falling apart and cause such turmoil after every argument. Something is amiss. Maybe some issues are not being addressed so they keep resurfacing. Plus why is it so hard all the time. You’ve been married less than three years and separated part of it. It’s unusually hard and it’s not due to stress, everyone has ton of stress ( it’s easier to blame on stress). What does your couples t think about the future of this?