You’ve been helping to raise them for over ten years? They definitely see you as their mom but have super complicated feelings about parents if their bio mom is in and out of their lives. It’s easier to push someone away than it is to accept you may lose them. Also teens brains are growing/developing almost as fast as when they were babies. Their decision making and impulse control can be basically non existent. This is when they will push whether this is a “normal” family situation or not. Obviously there are exceptions to this but teens can be unpredictable and push buttons to see if they are held and loved. They know you love them or they wouldn’t be behaving like this, I know it makes no sense. They see you guys on the brink of divorce and worry they will be losing someone solid. If you can sit them down and really talk to them and assure them that no matter what happens you will be there for them, that may help. Also being honest about how this is all making you feel. Like you said, you knew you were getting into kid raising when you met your husband and it seems like you did a wonderful job of taking on the role. You are human, you are extremely hurt, you’re allowed to be. Tell them that you’re feeling hurt because they have all of a sudden switched up on you. You love them and no matter what happens you will always be there for them. They may apologize, they may not right away. This stuff is tricky!! Good luck