I do the same high level, but I do it monthly. Non of the OOB reports will get at what you want. So two options
1. Run a query for the last 7days and export your data to excel (This is what I do).
Just run a query on the Delivery table for contact date is on or after 7 days ago.
then in the add data, add all your columns you want to sum up. I added an image of my query.
2. Build your custom report in the reports section. I added a video on how to get started with that. (Warning this can be complex, why I don't know, but its not as easy as in the video. Creating a Report in Adobe Campaign Classic | )