Recurrent thoughts about a mistake and the consequences of that

I sent an unhelpful email to my business partner and valued colleague, and in response she cut me out of our main project. I apologized as I’d not communicated what I’d actually meant and explained myself.

I’m hoping to work with him in our next venture and he’s still not engaging. I think “it’s not my best work, I’m not proud, I won’t do that again” and have felt through the shame and regret. Now I have intrusive feelings of ongoing shame and fear that I’ve ruined things forever. Are these indulgent emotions? How do I move past this?