I do wish my husband would start using my preferred pronouns. He's not spectacularly comfortable with the idea, and I try to understand and respect that.

I remind myself that he married a man, and I changed who I was long after we had a decades long relationship.

@swiftfoxfire I struggle to decide if I would call it change. Things changed over time, but you didn't change who you were, in a way. You simply learned more about yourself over time.
I think he should respect your pronouns, they are a part of you after all. Loving you means respecting that part of you.
Sure, there may be slipups, especially after such a long time knowing you one way, but I believe he should try.