Hey Copper Koda. I wanted to offer my empathy as I know how hard it can be to find normalcy again after a manic episode. I traumatized my husband during mine.

I agree with Christina. Go easy on yourself. Don't do anything that doesn't feel genuine. Your husband is looking for trust and faith through your letter writing and that is a fool's errand. I can see why he feels as he does, but it will not fix the situation. Write when it feels genuine and then spend time together when you can. Connect on every level possible if you feel inclined to do so.

The most important part is for you to learn how to manage future episodes. Understand warning signs and develop strategies to get help when you need it. Show your husband you're doing the work to avoid this in the future. That speaks volumes in comparison to a letter. Therapy is a great idea for both of you.

Med adjustment takes time. You're in good company if you have questions. There is a subforum here called Bipolar Treatments that you may find helpful.

Welcome, and I hope you find your experience here to be helpful and supportive.