You are welcome. If you want to resume syncing to your computer, undo what I posted above. Is there a reason you want to stop syncing? If space is a problem, you can move the photo Library to an external drive if desired.
One option to free up space would be to move your Photos Library to an external hard drive. Then quit/reopen Photos with the option/alt key held down and make the external hard drive file the system Library. Once you are sure all your photos are there, you can delete the Library from the internal drive if desired. Once you do this, the external hard drive will need to be attached to access/sync your photos.
Article if for iPhoto, but the basics are the same.