There are already a few articles on this site that talk about taking your data with you when you graduate:
Every Fall MDS Tech gets phone calls or emails from recently graduated students who want to access their Drivespace. Every Fall we tell them their data is gone, because we delete the accounts during summer.
Here’s another article with more detail on how to merge multiple mail accounts, calendars, drive material, etc.
Although this process is hardly painless, here are the step-by-step instructions—along with a few automated workflows—to help you transfer your data in less time and with fewer headaches than you might think.
There’s also no way to merge multiple Google Drive or Google Photos accounts together. But you can merge your files and photos into a different Google account.