D - I'm so excited about the project! You are absolutely correct that you need something to do. I think it will help you a lot.
Our 21st anniversary was just a few months after BD - and it was rough. Try to keep your mind occupied so you're not dwelling on it. Arrange something with some friends that evening so you're not sitting at home stewing.
I hate that you're backsliding - I feel so badly for you. You can come back up, D. You've just got to stop focusing on her, and put that focus right back on you. Got it?