I could have easily written this. I HATE that feeling. I have started either explicitly asking for a reply (or, more accurate, reassurance because 99% of the time that is what I'm looking for), telling her not to reply and that we would discuss it later, or asking for just a confirmation that she recieved it (a simple "thanks, got it" works well). It helps me not to obsess and I think it helps her know what I need.