Hello, metro0308!
Welcome to Apple Support Communities! From what I'm understanding from your post, you have enabled My Photo Stream on your iPhone, but you're having an issue enabling it on your Mac. I certainly know how great it is to have your Stream photos available on all your devices, and I would be happy to help.
There's another way to enable My Photo Stream, so try these steps instead:
- Open the Photos app on your Mac
- Click the "Photos" menu (upper left corner, by the menu)
- Click "Preferences..."
- Go to the iCloud tab (sign in with the same Apple ID you use on your iPhone if prompted)
- Put a checkmark next to "My Photo Stream"
For your perusal, I also want to give you the links for these resources we have about the My Photo Stream feature:
My Photo Stream FAQ
iCloud: My Photo Stream overview
iCloud: Set up My Photo Stream
Get help using My Photo Stream
Have a fantastic day!